sun: I am facing almost the same problem right now and i cant login to my QL id from my office computer and i had a feeling that i am blocked or something like that but i was surprised when i can access my account from any other computer and after the investigation i find out that i am not able to login to my account even from any computer in our company network.
so i guess that it is just a matter of restriction of from your company network admin otherwise try to delete the cookies and temporary internet files and let me know.
finaly i would like to thank QL admin and mods for thier efforts in this site