AltTab away from SC is dysfunctional

[tomos]

I think this recent, and appears to only happen with SC:

using AltTab to move to the next window no longer works as it should:
I have to press the Tab key twice to get to the next window.

EDIT//
this fixed after SC restart -- I will report back if it happens again. [Updated windows yesterday, maybe that had some weird influence :-/ ]
//EDIT

Wondering does SC for some reason 'swallow' the first Tab press?

This with SC installed
Version v4.21.1
Windows 7 x64

Can anyone else confirm this?
(Can check myself again on another Win.7 machine tomorrow)

[tomos]

Turns out that this was related to an always-on-top window (that I didnt notice cause almost moved off screen).

The always-on-top window (here was 'Everything' search window) always shows first in the AltTab 'dialogue' - then comes the window with focus.

Most software will AltTab as normal -- focus is already on third window when AltTab pressed, but with some other software (so far: SC & PhotoSupreme/IDimager), the Everything always-on-top window is read as having focus, and AltTab pressed once moves focus to the second in line i.e. the app itself, (then you need an extra Tab press to 'get away' from the always-on-top window to the third window).

Make sense?
Unimportant, but interesting, (says Tom procrastinating :p)

[mouser]

Make sense -- thanks for the follow-up