@amleto
That's what I tried to do lol, but it worked as normal. I did several tests to try and manipulate the example to be as close as possible (menu button, using an action to trigger, global/static functions, etc..) I just couldn't get it to fail. If I get 3 or 4 classes deep trying to replicate a problem; I've done what I can in a reasonable amount of time without just taking the shortcut of doing what I know works (but is more poor from a repeated code point of view.) But it's no matter because:..

@Talei
That fixed it! I didn't ever call hide on my main window.. but maybe something about this being a modal dialog (thusly pushing the other back) counts as hidden.. or something. Either way, thank you very much for the suggestion! You're obviously psychic lol. I'm guessing I've done something slightly odd with the Mainwindow's hierarchy or something (I have a separate class that controls the window in order to manage an overlay.)

@Wysota
Well I guess it's more obvious now, but it was just closing; which was part of my issue. A crash I have all sorts of tools to deal with . I had assumed crashing at first as I'm doing naughty things like passing member-function-pointers around; but alas, they all worked.


Thank you all for the input!