OK....possibly I'm getting fixated on cookies

When I try to log in for the first time I press submit end go to a blank screen. Possibly its trying to enter the classifieds but the software isnt working? I've checked the dbase settings and I "think" they are fine. Also I cant find an issue with the cookie settings in my
VB Cpanel, in PHP Myadmin, or in the config file.
SO now I'm really confused, which generally means its a really simple problem that I'm trying to make hard