First off, is this the *only* error you get? or do you also get some error about this line?

my %mp3tag = %$mp3hashref if ($mp3hashref);
[download]

if so the solution is to fix whatever is wrong on that line. If not, I'm rather at a loss for how to fix it...

As for what is giving you that Tk::Error message, it appears that someplace in &loadAlbum a run time error is being generated, a die or something. The way Tk appears to handle this without completely crashing is to eval any subroutine calls from a handler, which normally works great, however in your case the Listbox gets destroyed before the error is generated so when Tk goes to handle the error it tries to use whatever is the current widget (in this case the Listbox) and throws another error when it finds that widget has already been destroyed which is the error you posted.

Hope that's clear enough.
Tedrek