Slow run speed/"Rubberbanding"

[Rubiks]

It looks like this forum is for people who run servers, which I do not, but I think someone on this forum might know how to solve my problem.

I play on project 1999 and am having some strange lag issues. When I run, I go extremely slow. Someone said that to them it looked like I was "rubberbanding": bouncing back after every few feet that I move forward. Other than this the game runs fine. I had Dual Core CPU issues, but have corrected them with the fix on the forums.

If anyone has any idea what the root cause of this could be, I would really appreciate some help fixing this.

Thanks!