Hi, I believe I found a bug in your patch , which may be causing your problem. Your line

> if($case){$checkbutton5->set_active(1);}
[download]

probably should be

> if($use_regex){$checkbutton5->set_active(1);}
[download]

That would screw up the if-else clause, by cross-linking $case and $use_regex; but I'm still testing it. :-)