Some indirect answers that may be useful:
I don't tend to use the call stack view in the Studio debugger. For many cases where stack information is useful for debugging, I'll typically just add this to my code:
Then run it, and then look in the application error log (visible in Management Portal at System Operation > System Logs > Application ErrorLog, or via
do ^%ER) to see what the stack/variables were when it was called.
Also, you should be able to clear out locks (perhaps cautiously) in the management portal from System Operation > Locks > Manage Locks.