Unable to maintain steady 25fps + frame drops

[tvcapper]

Hey guys, hoping someone here might have some suggestions to my probs. When im trying to cap tv shows from my cable box I find that I can't maintain a steady 25fps. It will start out at 25fps then after about 2-3min it'll drop to 24.99757 and stay there abouts which in turn causes me to drop like 3-5 frames from a 9-13min clip.
My System and Settings:

Athlon 900
384meg pc-133 sdram
WinXP
40gig 7200 ATA 100 IBM HD
SBLive Value
Pinnicle pctv card

Capture settings

Vdub with HuffyUV (predict best)YUY2 (tried all 3 settings)
352x288 25fps PAL
Card hooked up to cable box via composite plug

Its not a major frame drop but I would still like to drop no frame at all if possible and maintain 25fps. I don't think its winxp cause same thing happened in win98.

I've tried the test the capture without the audio but I still drop the same amount of frames

Hmm I just tried the suggestion from someone elses post to uncheck "disable windows write buffering" and I only dropped 1 frame but my fps still dropped to 24.99 etc

Any suggestions appreciated

[FiEND]

i drop 20 frames per 60min, always have and looks like always will. with vdub and avi_io.

iuvcr though is different, it will drop 3 or 4 frames in a chunk or none at all but audio stays in sync so no real problem there.

[decipio]

Hmm, even if it is 24.9 you shouldn't notice it. So... don't worry.