Entering new character's name

[th0b0r0]

Hey there,
got some weird problem here.
Every time I try to create a new character, I can't get past the naming screen.
There's that blue cursor in the input field (I can even go away using tab), but regardless of what I type, nothing appears to be received by the game.

Only pressing return results in the game switching from fullscreen to windowed mode.
Looks to me as if alt is pressed the whole time, although it isn't...

any ideas there?