Problems logging on

Hopefully someone can help me with this-

I seem to be unable to log onto BT on my home computer all of the sudden (it works ok from other computers). I pull up the BT page and then go to the log on page and enter my user name and password. After I press enter it briefly shows a screen where it says to wait a second while it redirects me (strangely while it is on this screen I am logged on - I can see if I have any PM's, etc.). But as soon as it redirects me (or if I go to the redirect link) it sends me to beginnertriathlete.com/default.asp and I'm logged out.

Can someone tell me what I need to do to be able to log on? I recently had some security problems with my home computer and reset some things, but I don't have problems logging onto other sites such as email. Thanks for any help.

Drew