So XP's memory management sucks?
I beg to differ. I have had many misbehaving programs running on my XP machines and I've never had any problems with the other processes running along side them. I have however had many driver related problems.
All drivers, including codecs(at least I think so, I've been wrong before), have Kernel Mode access. This makes them particularly dangerous. ATI's crappy MPEG2 driver has caused my desktop to reboot on quite a few occasions.
This is not to say that XP is not without it's flaws, but I don't see memory management as one of them.