Continous, actually ALWAYs stall

Whenever I am testing out new skins or something with bots on any given map, it stalls out after a ki blast or what not, always, everytime I make it. Maybe you can find out by my computers set up:

AMD Athlon Xp +2400
512MB Kingston Ram
WD 40gb HD 7200 rpm
52x32x52x cd rw drive
geforce fx 5200 256mb Agp

I don't know why, maybe everyone has this prob, but I'm posting just to make sure.

Does it always stall? Or does it only stall when you're testing skins/bots/maps? Also, are you running the patch? Servers seem to continually crash since updating to the 1.2.1 patch, but I don't think anyone knows what's causing it yet.