I have some Modem Trouble

Ok heres the deal. I have a nice us robotics modem. It works fine for windows stuff, but when I try to play online games it sucks. My friend has the same Modem, and it works awsome in his pc. Most of the time I cant connect to the server. When I do connect i usually get huge ping spikes. From a ping of 170 or 220 ms all the way to 1000 0r 3432 ms and get the flush packet entity. Some times when I do connect to the server it works well. but for the most part it sucks. I play Counter-Strike on the net, and the server that I play on is through my ISP. I want to know if there are any tweaks or fixes for this kind of problem. Should I use a dialer other than window's. I have the latest drivers for it, and it still works like crap. Here are my system specs for some reference.

Athlon 600
512 pc100 ram
tdk-comp motherboard
with via kt133 chipset
3d prophet 2mx
Us Robotics 56k fax modem ISA on Com 2 Irq 3
the us robotics number is 005687-53

Thanks a billion for any help that you can give