Linksys router wrt54g is slowing down my connection

I am haveing issues with my linksys router as well. when I hook my internet connection directly to my computer it is lighting fast but when I have it going through the router it is slow or timing out some of my other software. Someone else posted going to speedtest.compufirm.net/ to test your connection and mine was 4502 download and the upload came back with an error. I have tried this test on other sites and it cam back fine. This problem is an off and on problem and it started a week ago.

Any help would be great!