XBMC was locked,becoz i entered wrong password 3 times Help!

Hello Folks,
just now i did stupid things: i entered the wrong password 3 times in the XBMC of my Apple TV2 (i activated the Admin password in the XBMC), now i can’t enter the XBMC anymore, it’s totally black screen (Blackout) and i can’t enter the right password (i got rite now the right password), after i press the “XBMC” Button on my ATV2 with the remote.

btw: i unstalled the XBMC with ATV Flash Maintainance, and then installed XBMC again, but it doesn't work, as long as i press XBMC Button and enter it, then blackout.........

Where is the configuration file of XBMC, which contains the Admin Password of XBMC? I want to delete it

Please help me!!! thanks a lot