dvd ripping does not work with external drive

[fnordz]

hi,
i got a small problem,i bought a plextor-px-b120u external bluray drive.
ripping blurays works fine,but with dvds makemkv is not able to open the disc.
i can rip them without a problem if i use ripit and afterwarts makemkv,
but i would prefer i could use only makemkv
same dvds in the macmini 2010 internal drive rip fine with makemkv.

debug crashes makemkv,so i post the errors i get.

make mkv version 1.6.3

Drive BD-ROM PLEXTOR BD-ROM PX-B120U 1.06 has RPC protection that can not be bypassed. Change drive region or update drive firmware from http://tdb.rpc1.org. Errors likely to follow.

Failed to decode audio/video data for title #1 - invalid mux or internal error, title skipped.
Failed to decode audio/video data for title #1 - invalid mux or internal error, title skipped.
Failed to decode audio/video data for title #2 - invalid mux or internal error, title skipped.
Failed to decode audio/video data for title #2 - invalid mux or internal error, title skipped.
Failed to decode audio/video data for title #2 - invalid mux or internal error, title skipped.
Failed to decode audio/video data for title #2 - invalid mux or internal error, title skipped.

thanks.

[mike admin]

Please try version 1.6.4 with DASPI installed.