upgrading from php 4 to 5

I updated my server tonite using yum and my webhost’s instructions I’m now running php 5.1.6 and mysql 5.0.48 from older ver 4 of each. Now when I check my sites, the don’t render at all. Source code is all blank. Running WP 2.3.1

I started by taking out the .htaccess file and nothing changed. Then I re-uploaded the WP code files and still nothing. Any ideas from anyone what I did?

strangely enough my mint stats work ok /mint/ but not WP 8(