Cannot upgrade or access admin after moving to different server cluster

Hi,

I asked my hosting company to move me to a newer, faster cluster in their servers thinking it would be a simple matter because I wasn’t changing URLs… After the change I had some problems with the advanced-cache.php/wp-cache in the two of my blogs I had installed the plugin, but solved it after unplugging them and erasing the cache folder, at least in one…

The problem is I made the big mistake of uploading the 2.2 version of WP (I had 2.1.2) to one of those blogs. Now, when I try to load upgrade.php this comes out:

Fatal error: Call to undefined function wp_redirect() in /mounted-storage/home58a/sub001/sc30883-FDZZ/secretia.com/wp-admin/admin.php on line 8

and if I try to use anything in the admin interface I get this:

Fatal error: Call to undefined function wp_get_current_user() in /mounted-storage/home58a/sub001/sc30883-FDZZ/secretia.com/wp-includes/capabilities.php on line 446

The previous cluster (in case it helps) was
/mounted-storage/home39c/sub003/sc30883-FDZZ/

Could someone please give me a hand? I need to solve this ASAP, I literally LIVE and EAT from this site ??

Thanks,

Diego