What keyboard layout do you use to play URW? Is it an English US layout or some other one? I remember a long time ago I had a different issue with Hungarian keyboard layout that Sami had to fix for me.
Thank you for the idea. It's American layout (ANSI keyboard). I actually thought about the layout types, too, so I tested that keyboard on another computer and it worked. So the factors of keyboard types or drivers are excluded. The problem should be more likely with that computer itself, on which the command doesn't work.
A funny thing I discovered in one of my attempts to fix this problem is that I can't assign
"ctrl"+
"," as a shortcut key of the system or any software on that computer, however they become assignable after changing the system language to any other language than English (UK,US... no matter what type of English it is).
Changing system language doesn't fix the issue in game, though. From a positive perspective, it helps locating where the root of the problem is, I guess.