I'd noticed sometime when capturing analog sources the resulting framerate may slightly vary from the specified figure. For example, 29.63 instead of 29.97 (NTSC) or 24.96 instead of 25 (PAL). Is this normal? Is it worth adjusting the framerate for the captured file? I'm using iuVCR...

BTW it's only happened if I try to convert mono to stereo at cap time.