My wordpress blog is hosted with Dreamhost and I found this in their support wiki:
If you have “blank pages” in WordPress with wp-cache turned on after you upgrage to PHP 5.1.2 – there is simple fix to solve the problem:-
1. Open wp-cache-phase2.php file* in your favourite text editor
2. Find out wp_cache_ob_end function
3. then inside that function find out line with: ob_end_clean(); (it should be line 219 or about)
4. and finally replace that line with: ob_end_flush();
I had already turned off wp-cache, but this solved my problem of a blank screen on every first load.
