[User32?] REGRESSION: Start menu does not close when opened and clicking on desktop

I updated from r69229 to r69244

open the start menu:
then click on empty space on desktop.

Expected result: startmenu closes
Observed result: startmenu stays open

If I had to quick-guess (without reg-testing or further research),
I'd fingerpoint to

r69233 | jimtabor | 2015-09-15 02:15:16 +0200 (Di, 15 Sep 2015) | 2 lines
[User32]

• Patch by Alex Henrie : Send BM_SETCHECK before WM_CAPTURECHANGED and add tests.

COULD imagine, this is a side-effect of that task (not sure)...
Please correct me, if I am wrong.
Can anyone confirm the symptom?

CC jimtabor