I can't get my .srt subtitles work.

I've renamed the .avi and .srt the same
I've put them in the same folder.
I've installed vob sub.
I've set them to open and play in different players... VLC, Bsplayer and WMP

Any ideas? I've also been having trouble with AC3 in bsplayer, the audio lags behind the video by a fraction of a second in ALL my ac3 files.

Could it be my new cpu and ram? I never had this trouble with my old Athlon 2800XP and DDR333 ram, I've now got an Athlon 64 3500 with DDR400 ram

Thanks.

EDIT - .sub/.idx files seem to work ok in bsplayer