Required two monitors to replicate.
<img src="http://img197.imageshack.us/img197/7489/clipboard01jw.jpg" border="0" />
Steps to reproduce:
1. Try to right click to modify polygons in "Edit image dialog" in your secondary monitor
Observed result:
The right click menu don't appear
Expected result:
The right click menu should appear
If you move the window to your primary monitor, the menu will show after the click just fine.
Operating system & service pack:
Windows 8
Construct 2 version:
123.2