www.makemkv.com

I've tried with two discs, an old one and a recently bought one.
Always the same errors.
And i'm unabled to attached the log file (too big ? 61Ko)

Debug log started at Thu Jun 18 18:28:37 2015 , written by MakeMKV v1.9.4 win(x86-release)
Using 524544KB for read cache.
001005:0000 MakeMKV v1.9.4 win(x86-release) started
001004:0000 Debug logging enabled, log will be saved as C:\Users\Christophe/MakeMKV_log.txt
003007:0000 Using direct disc access mode
003025:0000 Title #1 has length of 90 seconds which is less than minimum title length of 120 seconds and was therefore skipped
003025:0000 Title #2 has length of 20 seconds which is less than minimum title length of 120 seconds and was therefore skipped
003028:0000 Title #3 was added (13 cell(s), 1:45:38)
005011:0000 Operation successfully completed
005014:0000 Saving 1 titles into directory E:/MakeMKV/LEON
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 24186880, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 40105984, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 74110976, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 98078720, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 107909120, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 114536448, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 123613184, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 132704256, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 133722112, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 135485440, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 137388032, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 141221888, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 142297088, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 151611392, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 154009600, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 159498240, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 162183168, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 167247872, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 169678848, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 172814336, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 174282752, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 175812608, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 179294208, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 181254144, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 191318016, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 198385664, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 199622656, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 201828352, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 202848256, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 206227456, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 207587328, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 210026496, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 212840448, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 216008704, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 219064320, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 219912192, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 222441472, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 223889408, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 227907584, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 230258688, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 234547200, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 235454464, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 236169216, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 236832768, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 239454208, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 242327552, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 248844288, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 250621952, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 252977152, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 255942656, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 257826816, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 262105088, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 264583168, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 269236224, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 270929920, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 272723968, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 273684480, attempting to work around
004004:0000 The source file '/VIDEO_TS/VTS_01_1.VOB' is corrupt or invalid at offset 274511872, attempting to work around
001003:0020 DEBUG: Code 5 at 2|CPQ}j!+VKgSsS!ul7L:29396552
001003:0020 DEBUG: Code 0 at 2|CPQ}j!+VKgSsS!ul7L:29396828
001003:0020 DEBUG: Code 0 at 2|CPQ}j!+VKgSsS!ul7L:213130099
001003:0020 DEBUG: Code 0 at 2|CPQ}j!+VKgSsS!ul7L:121267684

[cut here because too long to submit]

001003:0020 DEBUG: Code 0 at <TH?hld8vxKG;N$5II2[\:29398967
001003:0020 DEBUG: Code 0 at <TH?hld8vxKG;N$5II2[\:29398967
001003:0020 DEBUG: Code 0 at ZE=~A,+w{$]Rgb,`=:213131893
001003:0020 DEBUG: Code 0 at ZE=~A,+w{$]Rgb,`=:121263406
001003:0020 DEBUG: Code 0 at ZE=~A,+w{$]Rgb,`=:29393907
001003:0020 DEBUG: Code 0 at <TH?hld8vxKG;N$5II2[\:29398967
001002:0020 LIBMKV_TRACE: Exception: Error in p->FetchFrames(2,true)
005003:0000 Failed to save title 0 to file E:/MakeMKV/LEON/LEON_t00.mkv
005004:0080 0 titles saved, 1 failed
005037:0204 Copy complete. 0 titles saved, 1 failed.
Application exited at Thu Jun 18 18:30:26 2015

You are getting the same errors (The source file ... is corrupt or invalid) on two different copies of the same DVD title, or two different DVD titles have the same type of error?

Two different copies of the same DVD title (there is only one title on DVD).

It's OK now with the new 1.9.5 release.