I've recently decided to go ahead and buy CSS from steam and lately in servers I seem to skip frames..pretty badly sometimes. I would stand in one position for 2-4 secs before my screen shows me at my intended location(dead or not) and all my weapons would highlight as if I never had them. This may just be server lag but everyone else on the server(s) run fine, zombie servers it runs alright with some lag depending on how chaotic the map is.

edit: Steam is fucking retarded..even with the update they did it still crashes with XP..