Internet problems

I just changed my internet connection (via dsl) from Internet connect sharing to a router. My vista computers and one xp computer have no problem uploading results. Two xp computers (one xp home and the other xp pro)cannot upload results. Under the transfer tab, it tries to upload, then wants to try later. Each result uploads to about 44%. The message tab states that maybe the server is unavailable.

All of my computers except the xp pro (new computer) worked flawlessly before. All other internet functions work well. I am baffled and would appreciate any help.

Thanks,

Ed Harte