... the answer is probably yes..... from my experience with threads under Tk and Gtk2.

....the big glaring hotspot in your code, is that you try to create your threads from a button callback.... most of the time that fails, due to the way Perl threads get created.... you should always avoid making threads from a gui callback..... sometimes they work but are often crashers.....

...see Reusable threads demo for a way around the problem, by creating your threads before any gui code is invoked.... thread safety with all gui toolkits is a problem....there are alot of workarounds however