can't log into some secure sites

[SlowRider]

I believe my problem is hardware but I am not sure....
I built my computer last year. I can't remember the specs right now but can get them if needed. I know I have a dual core intel, 2gb ram, 250 HD, XP SP2

problem:
I cannot log into some secure sites. I can log into ebay but not paypal. I can log into facebook but not my webmail (bellsouth.net). everything else seems fine.

Diagnostics done:

1. reloaded and tested windows from no SP to fully patched SP2
2. Tried multiple browsers
3. tried different wireless cards
4. researched till google gave no results

I am not sure what to do next. The computer is really fast and runs great. If I can just get past this issue... I have never seen anything like this before in all my computer travels

thanks for any suggestions...

 

[SlowRider]

Got Good news... after everything I got it working.

I had to change my MTU to 1492 and reboot... now the computer seems even faster AND I can log into all sites...


Thanks for all the help
I guess I just needed to ask for help to figure it out...