We are trying to analyze a w3wp memory dump using windbg and we found that w3wp process is crashing due to stack overflow. I loaded the psscor4.dll and got the call stack by iss
Such are the joys of debugging optimized code. If you use !sosex.mdv, you'll at least get the datatypes of your locals/args. Then you can run !sos.dso or !sosex.mdso to see the objects on the stack with their types. It's usually not terribly difficult to track down the arguments this way, though it does not always work.