Lag Spikes

Hello everyone, this is my first post, and I hope I'm not doing something wrong, if so please correct me (:
This is the thing:
Before the spring patch my ping in UK servers was 52-57, after downloading the spring patch I got an "Error :File change W(2007) L(0) crossfire.exe", I didn't know what this was so I tried my hard to see what it was And I thought I would be the antivirus, so, I disabled it downloaded the game and when I tried to apply the patch ( with the antivirus off) It did say serveral times "Fail to Download the patch" but when I'd try to download the patch again It'd worked till a new "Fail to Download the patch" till I finally Have it.
Now when I enter the game I have an enourmos lag spike my ping is 100-400-600 and I can't seem to find a way to lower it, even turning my anti virus off.
I tried playing another online FPS, soldier front aka Special force and I don't have any lag or spike, only on crossfire.
When I try to kill the guys (and girls :P) look like ninjas! they disapear in front of me! and other times they freez and I keep shoting at them and what happens? I die and they weren't hit. I really like CF but I can't play like this...
Is there anything you'd do? Is it Server Lag?What do I do?

Thanks in advance (:

sL!te_exTr3M