Minor and probably Rare.. but annoying!

Desc: GooTool hangs if you click the Save button at the "wrong" time.

To Reproduce:
Double-Click a goomod file which is already installed
GooTool shows "Are you sure you want to install this addin?" -> Yes
GooTool shows "This addin already exists.. Are you Sure?" -> Yes
Click Save in the 1-2s pause before the "Addin Installed!" message appears
"Addin Installed" message box appears (but often empty / incomplete) and can't be closed
GooTool is "dead"... End Process seems the only way out.

Only seems to happen if the addin already exists, if it's "new" then Save doesn't respond to being clicked during the pause.

PS. Can't comment in mantis, but I'd hold off on the "Validate PNG" thing...
I'm beginning to suspect the problem is (maybe, sometimes, always?) related to the size of the image, not the format. Have posted this hoping to resolve the issue one way or the other.