Using ActiveState Perl but not their debugger. The problem originally showed up the the class I'm working on to support IE::Mechanize. The code I posted is greatly simplified from the class and entirely different. The problem has persisted across all changes I've made to date so I'm inclined to think it is likely a problem in Win32::OLE, PERL, or some combination. Testing suggest that it may have something to do with memory management and/or reentrancy, but that's just a guess.