Can’t log in as *any* user including admin

Hi,

Moved the site from one dedicated server to the other (same domain name). Updated the wp-config.php with the new database settings. The front-end of the site works perfectly fine… all entries, comments, etc. show up.

Old server… php 5, FedoraCore3, Apache 2. New server… php 4.3, CentOS, Apache 2.

When I go to /wp-admin/ I get a blank page.
When I go to /wp-login.php, I get the login form ok. When I enter a bad username/password, I get a message saying its incorrect. When I enter valid un/pw, I get a blank page.

replaced wp-login.php and the entire wp-admin directory of files. still can’t log in.

i can have my password reset and successfully receive the new pw by email. however, every attempt to login results in a blank page.

thanks in advance.