AIW 128 pci, MMC 7.2 and SVCD capture?

I'm a total video capture newbie, but I'd like to capture SVCD video
directly. Is this possible with my old AIW 128 16MB PCI? I've set the
settings to 480x480, about 2MB bitrate, but my only options for sound
are 22KHz. I'm using the latest software for the card from ATI's
site. The VCD preset is too blocky and fuzzy to suit me. ATI's site
says I downloaded MMC 7.2, but the help icon on lauchpad says
launchpad is 7.1.

I'm running an AMD Athlon 1800+ on an ECS K7S5A motherboard. 80BGB
hdd with WinXP home, 120 GB HDD dedicated for capture, master/slave on
IDE 0. DVD drive as master on IDE 1. 512MB PC2100.

I always get stuttery capture even with only 50% cpu usage, noticeable
only in slow panning shots. I also see where I should be able to
select IPB (if I have the terminology correct) with 12 of P, 4 B (or
thereabouts) according to the help files that came with the drivers.
I can't change it from 4 and 2. ???? Should I disable my NIC when
capturing?

I can't capture at full-frame, full-motion MPEG2 with this setup, uses
100% cpu with dropped frames. Does this sound right?

Here are the drivers and files I downloaded from ATI:
WXP_R128_6_13_3279.exe
Windows XP Display Driver for ATI RAGE 128 / RAGE128 PRO

MMC 7.2 no DVD

DVD 5.0 upgrade

It's all so confusing.