I have the weirdest bug I have ever seen: I cannot login into the admin area.
I enter the username and password correctly, I click Log In and the wp-login.php page simply reloads, without any error messages.
I have tried on Firefox, IE, Opera, Chrome - same thing happens. If I enter a wrong password I get an error message. If I enter it correctly - NOTHING.
The rest of the site is working perfectly, users add comments, I get e-mail notifications etc.
I have no idea what might cause this. Please help!