Steam overlay issue?

[Endoran]

I have F7 bound as my steam overlay key, and it works in every other steam game including Last Light, but shift+tab also still seems to work in Last Light for some reason.
It's annoying if I'm trying to swap items while running, and the shift+tab shortcut doesn't work in any other game I own, only Last Light. Is there some fix for this?

[Endoran]

Shift+Tab will also only open the overlay, not close it. My F7 shortcut opens and closes the overlay, so it seems to be some weird baked-in setting for the game.

[cuss]

I've rebound the overlay but shift+tab still opens it in my game too.
A fix is doubtful, disabling it for this game might be the easiest solution.
(R-click game in Steam, select Properties, disable Overlay)

[Jurassic Fart 1]

What pisses me off with that gawdamned overlay is that it keeps friggin' popping up when I sprint using SHIFT+W. That is NOT how you summon that damned overlay! And I'm not accidentally touching other keys; I don't have fingers as fat as knockwurst!