Vanishing Available Disk Space in Mountain Lion

[MarkN]

I ripped a couple of blu ray discs, converted certain chapters with Handbrake (concert blu-rays), moved the mp4's off and then deleted the mkv folders. I noticed that my free disk space didn't get replenished after deleting 36 GB files. I then tried it again to see what was happening.

I ripped another blu-ray.

Finder reports: 98.04 GB available
Disk Utility reports: 55.35 GB available

The mkv folder is 31.2 GB
I moved this folder to the trash, and then emptied the trash.

Finder reports 66.84 GB available while emptying Trash

It took a good 20 minutes or so to delete the file and then the disk space usage was:
Finder reports: 98.04 GB available
Disk Utility reports: 31.34 GB available

I ripped another shorter blu-ray and it now shows:
Finder reports: 123.25 GB available
Disk Utility reports: 49.15 GB available

It's been a long time since I did any programming, but it seems as if makemkv could be reserving a big block of disk space for its output that doesn't get freed up upon deletion, but it does reuse it next time.

Does anyone know what is going on? Is this a Mountain Lion or MakeMKV bug?

[MarkN]

I think I figured out the problem.

I wasn't aware of a Time Machine option of "Local Backups" that keep a copy of everything on my laptop. I disabled local backups and my available space shot up again to well past what I expected. All is well with MakeMKV!!!