Normally i could use combinations like Alt-G-C or Alt-G-F, to assign status icons (check/flag). But instead i am toggling the first menu item of my main toolbar now, keeping me from finishing the shortcut.
It used to work a few weeks ago. Any idea, what could be the reason? 
Are you letting go of Alt before pushing the first letter? They need to be pushed together, then the second letter on its own.
Leo, sorry, i found the culprit. It was some hotkey in the settings of another new small application, that hogged the Alt-G combination, as i found out (i don't use them anyway, so i voided the hotkey combination). After i saw Alt-B.. combinations work in Opus, as they ever did, i knew, the reason had to be somewhere else. 
Just for your interest, actually you don't push both keys at the same time, since you would end up typing the wrong key first in maybe 50% of all cases, triggering the filter to pop up. So pushing Alt first, holding the key, then pushing the first character, let go, then the second one, does the job as intended.
