Have you tried clearing you cache/cookies/active logins?
Don't take this wrong, but you sound like those foreign-country based help line assistants !
While I realize they have to go through their scripts and can't have an original thought, I patiently explained to her before she could run me through it that I had done the following:
1) cleared cache, cookies, browsing history, etc.
2) got a new password (which also didn't get me in)
3) had tried 3 computers (two of which are rarely used) and had similar experience (couldn't log in)
4) had gotten in ONCE by using Firefox instead of IE9
5) later couldn't get in with even Firefox.
I think #3 above says a lot about what I finally said to her:
"Doesn't it make sense that if I can't get logged in using THREE SEPARATE computers that it is something at YOUR end?"
Her response was "I'm not authorized to say anything about something like that". That kind of told me that I wasn't the first one having the problem. She put me through to the advanced team, but after being on hold for about 10 minutes I hung up.
Lo and behold, 10 minutes later I was able to get in using Firefox. I haven't tried IE9 again. I just wanted to get some items listed.
****
Get a clue eBay...fess up when it's your fault.