shortcut for changing brush size aren't working

[Noë]

I have a kind of big problem..
Yesterday the shortcuts for changing brush size ([ an ]) were working fine, and today they won't work!
I restarted my computer, and normally the problem should be solved when I did that, but it wasn't..

Please help me! I have to change size manually now, and it takes a lot of extra useless time.

love,
Marleen

EDIT; ooooh I'm so stupid! I just had to use Ctrl + Shift to switch the keyboard settings...
Sorry for posting a whole thread about this!