I upgraded to WP 3.2.1 today, after first changing the MySQL version to 5.x as required by WP. The PHP-version is also set to 5.3.
After upgrading WP I found that my subdomain sites wouldn't work anymore. I only got error messages about some older PHP-version 4.0.something, and that WP required 5.X. This was when visiting the subdomains, but the main site works fine.
Just to be clear, the subdomains have been working fine for more than a year, it was only after upgrading to WP 3.2.1 that this became an issue.
Adding subdomain blogs seems to work fine, I'm on the main dashboard as network admin, and just punch them in. It's when I try to visit them I get that error, and no dashboard.
Any ideas on how to fix it?