Why it need StackWalk64 ? Do you use a windows-64 bit version ?
You can call the *64 functions without running a 64-bit version of windows or the dll. I had to forward SymLoadModule64 to SymLoadModule to solve an issue in Process Explorer. This however means that more and more apps are going to use the *64 funtions and that our dbghelp needs an overhaul (any volunteers ?).
Cheers,
Paul.