when I do the test page it shows all green yet when I go to login I get this error:

Fatal error: Unknown(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition adodb_mysql of the object you are trying to operate on was loaded _before_ the session was started in /export/web20/alpha/clair001/www/phpopenchat-3.0.0b2/include/class.Chat.inc on line 1130

can anyone tell me how I can fix this problem?