in reply to
Multithreaded Server Crashes under heavy load
Have you considered attaching a C debugger to the crashed process (the "Debug" button in the Error Reporting popup) and getting a C callstack?
Or atleast posting "To see what data... click here"->"Error Signature" area, or slightly better, "To see what data... click here"->"technical information about the error report, click here"->upper text box (but you can't right-click copy that information AFAIK, I'm most interested in "Code:" number, if its not 0xC0000005, you are one really lucky person and the crash is much more interesting).
What version number of Perl are using, and ActivePerl or Strawberry Perl?