***Wonderful error message***

[mooli_deejay1]

hi
today i see the new error message in my website  , i could login to the admin area and user area but today i can't , when i try to login and type my user name and password the main page loaded and i see the welcome message but suddenly the page return to the main page and doesn't login  , i set my cookis and i install the opera browser even but i can't login  , i don't know why ? , i was give my user name and password to my friend and he could login with my user name and pass but i can't  .
somebody help me out plz .


tnx...

[Joachim Müller]

don't bother to post a link to your site that causes issues, we're of course mind-readers. Don't post details about your client (OS, browser, security software) etc., they would be helpful to trouble-shoot your issue, so why should we have them?