Lag Problems

[@pocalypse]

hi'z
ive got a major annoying problem. in the last few dayz my cs has been laggin like a bitch even tho my ping is like 50 or so

ive got a
p4.2.53, 512mb ddr-333 ram, gf4 mx440, sblive 5.1, optus net cable.

the game has been working fine for a while but in the last few dayz its just gone crazy
wehn eva i go near a bunch of players it starts laggin like a bitch

plz help us out