Just tried to upgrade a customer from 2.01 to 2.7.
I do have a backup and even a complete download of all files on a separate HD.
On this particular site MYSQL 5.0 is on a non-accessible shared server.
PHP version 4.4.7
PROBLEM
Site Admin Log In is blank. Tried manual, http://shorecatch.com/wp/wp-admin/upgrade.php This is also blank.
I did delete old files as per Upgrade: Detailed Instructions via FTP except for one which is would not be a good idea - "php4.core" @ 8.3 MB