Look like im facing the same problem. i cannot log as admin@localhost from the first time, I've tried to do fresh install many times it didnt work also.
once i enter the admin@localhost and password admin. It takes me to the same site again. then i checked the error_log file. i found this:
[08-Jan-2008 05:34:01] PHP Warning: PHP Startup: Unable to load dynamic library './phpshield.5.2.lin' - ./phpshield.5.2.lin: cannot open shared object file: No such file or directory in Unknown on line 0
Then I did some searchs in the web. i found that maybe i need to have phpshield.5.2.lin (its a loader) in the script folder and configure the php.ini. did that and did another fresh install with phpshield.5.2.lin in the folder..
i got the error_log changed to:
[08-Jan-2008 08:29:34] PHP Warning: PHP Startup: phpSHIELD: Unable to initialize module
Module compiled with module API=20060613, debug=0, thread-safety=0
PHP compiled with module API=20050922, debug=0, thread-safety=0
These options need to match
in Unknown on line 0
need some Help