We migrated our web site to a Windows 2003 server a few months back, everything has been fine, and pretty much still is!
However we are getting some complaints that when uses are browsing, trying to post (to new and old threads) they´re waiting for a response ("web site found, waiting for reply.." etc.) then a white screen appears and the page stops loading. I´ve had this myself once or twice while browsing the web site.
What prompted me to post on here was a user posted in an already existing thread and was shown a white screen after submitting his post. The post appeared in the thread, but it did not register as a new post in the "new posts" search or the thread listing on forum display.
We´re running Windows 2003, IIS6, PHP5 and MySQL5.
If anyone has any suggestions as to why this is randomly happening, please let me know!