/wp-admin/index.php gives blank page

I’m a longtime WordPress user, and today encountered a problem I haven’t had before.

I’m in the process of moving my sites from one hosting company to another. I’ve copied all items and the database tables over. My site displays well on my new host, but any time I attempt to access the wp-admin section, I get nothing but a blank page.

I’ve seen other posts in this forum discussing how a blank line at the end of a file can cause this. To remedy this I’ve checked all of the php files in the root for blank lines at the end (wp-config, wp-load, wp-settings, etc.) I’ve re-uploaded the wp-admin and wp-includes directories fresh. I’ve repaired all of my database tables, and I’m not getting anything.

I’ve set WP_DEBUG and installed xdebug on my server. I’m not getting any errors, the code just seems to be stopping.

Looking at the xdebug logs, in /wp-admin/admin.php, nocache_headers is being called, but update_category_cache is not. The headers in the browser aren’t showing some of the values that should be set here by nocache_headers and auth_redirect.

I’m sure I’m missing something stupid here. Anyone have any ideas what it might be?

The new site is on a media temple (gs) running their version of Debian. PHP version is 5.2.14. WordPress is 3.0.1. All plugins are running on another production site and are stable.