[pest]

This a bit of a long shot, but it screwed me up once - go into multiplayer options and make sure you have your connection set to the proper setting. When mine got changed somehow to 56k, it gave me the slideshow effect, especially with the firing. Your pc should be able to run it fine, but you cannot have your video settings turned up. If that doesnt help, turn all your video and andavnced setting as low as they can go and then turn them up one at a time until you get frame rate hits again. Good luck.