Sorry about the misunderstanding, I was wrong calling it tilde, because that's this one: "~", as I know now. The key that I really meant is in fact the "^"-key directly under Escape. I checked EAW, where I can't open the console, too. But I know for sure that it worked not too long ago. Don't know what happened in the meantime, but in other programs the key works just fine.
edit: I tried the Vanilla 1.04 instead of 1.05 beta RC9 with the same result.
-- When the going gets weird, the weird turn pro.