I don't even know how to explain this. The only thing I can think is 'why am I working with a windows server?'
I am renting a dedicated 1and1 server - I installed PHP myself - with fast CGI and caching (pretty sure I checked OK on something about dynamic caching for PHP when I installed it.)
Every few hours of intensive php processing - my pages start locking up - usually just showing blank pages - with no errors whatsoever.
Just now, I checked a page - let's call it a.php - and it was showing the results of b.php - I thought I had been hacked!
Simply restarting the IIS server however, fixes the problem.
Any ideas / help / knowledge on similar problems with windows 2008?