I used to be able to use steam overlay when I just started playing SK(months ago).
Then it had stopped working all of a sudden(months ago).
But a few days ago, it started working again ALL OF A SUDDEN.

Today, it has stopped working AGAIN ALL OF A SUDDEN.

I did nothing before it starts/stops working. It just stops/starts working suddenly without knowing touching etc.

I didn't really care about steam overlay when it first time stopped working but I recently realized that the in-game support link only works on Steam Browser(not my chrome/firefox/safari etc) so I do need steam overlay this time. Since the Halloween patch, game sends me to the middle of a map and need to call GMs for that reason often -.-

So the problem is even if I push the command "shift+tab" the overlay doesn't come up.
I have already checked the settings(Preference->In-game) and it SHOULD be working in theory. Already checked Spiral Knights-> properties->general too, it SHOULD be working in theory (again).
Yes, of course, I've already restarted SK 3 times, Steam, even computer itself. BUT shift+tab still doesn't work. Tried to change the key settings, but nope, can't change the key settings unfortunately.

Do you know how to fix this? I REALLY need the steam overlay for the steam browser to call a GM when I stuck due to the spawning bug -_- Please help me fixing this

By the way, I'm on Mac OS 10.7.5 if it matters.