Extremely slow wall movement

1

I am making a two player driving game in flash MX, where the cars drive around and shoot each other. I have extremely limited knowledge of actionscript, so i got some help from a few people online with the basics. everything about the basic engine works, except that you can extremely slowly move your way through walls. I have no exact idea what the problem is, because i know so very little AS, but i think it might have something to do with x and y not being properly defined. can someone with a little more knowledge of AS help me out here? i have tried quite a few other forums to no avail. keep in mind the .fla im posting is just a test engine, most of the details arent set up.