[duncanj]

My iMac routinely locks up when it gets overly confused while playing a DVD. This is probably the only major annoyance the computer gives me, but it is annoying. Perhaps if I used VLC I'd have better luck, but DVD Player and Front Row both cause problems.

[protomyth]

That might be a hardware issue, we had a machine doing that and had to get it fixed (not sure what was wrong - applecare with someone else taking it in).