dropping frames after about 20 minutes

[jeex]

i'm trying to capture an 85 minute video..

i'm just the picvideo codec, quality set to 20/yuv2/640x40/ cd quality audio

capturing to a seperate 80gig 7200rpm harddrive
p3 800mhz/ 384mb ram/ ati aiw 128 (w/ newest drivers)/ win xp pro



during the first 20 minutes or so of the capture i had dropped 3 frames.. during the next 2 minutes i grew to 220, so i stopped the capture.. i had formatted the harddrive that i am capturing to, no background applications are running, & dma is enabled on all harddrives.. cpu usage was hovering between 60% & 80%.. there is no type of screen saver, power saving or anything set..

i was using avi_io, but i kept getting critical errors during my captures.. so i went to virtual dub, using the same settings.. everything was going great, until about 20 minutes...

any advice on what might be causing this?

thanks for any help that can be provided

[jeex]

trying not to becareful.. *bump*.. oh.. sorry about that =)