I am coming into this late. Since you said you where able to connect at one time, my question is, 1) do you have auto-update turned on for your XP Home? (This question would address the SP2 for XP which recently came out).

If you answered yes to my question I suggest you look at your firewall setup and possible disable it to test to see if you connect. If you do, open your IP port to allow and accept packets for RDC (3389 I think).

Dennis