I'm getting a 500.0 - Internal Server Error when a user signs ups for an event. The user gets signed up despite the error, they just have to click back and go back to the event.

I am (fortunately or not) running the latest versions of everything.
MS IIS 7.5
PHP 5.2.11 in FastCGI mode
MySQL 5.1.39

Module FastCgiModule
Notification ExecuteRequestHandler
Handler PHP_via_FastCGI
Error Code 0x00000000
Requested URL http://www.xxxxxxxxxxxxx.com:80/index.php?q=node/116/signups/add
Physical Path C:\inetpub\xxxxxxxxxxxxx\index.php
Logon Method Anonymous
Logon User Anonymous

This seems like the only issues I am seeing with this server configuration. Let me know if there is anything else I can provide you with.