http://bugs.winehq.org/show_bug.cgi?id=57097
--- Comment #9 from mata sutupud@yahoo.com --- Setting LC_ALL can barely be considered a workaround.
The LC_* sections should not really have anything to do with the keyboard layout. Or which LC_* subsection concretely needs to be set as to not override just this, without affecting anything else.
I can only say that when I disable that switch, it works for me in any locale and keyboard layout combination. With that switch in place it doesn't.
So something clearly seems to be wrong with that logic.
https://bugs.winehq.org/show_bug.cgi?id=58247 also might be related.