All of a sudden my app is handing this out in the application event viewer:
EventType clr20r3, P1 w3wp.exe, P2 6.0.3790.3959, P3 45d6968e, P4 app_code.ahowircm, P5 0.0.0.0, P6 4b167253, P7 30, P8 0, P9 system.stackoverflowexception, P10 NIL.
Nothing has changed since yesterday, and everything worked fine before. The server is running some .net 2.0 webservices on top of Windows Server 2003.!!!!!
Edit:
Also I'm running this on two servers, 2008R2 and 2003, the exact same code, on 2008R2 it works fine, but on 2003 it stops the application pool.
This usually points to a runaway recursive call (on purpose or not). Hard to tell without seeing some code.