Being precise is good.
Unfortunately, I'm not familiar with international keyboard layouts and their compatibility with the game, so hopefully someone who is can add their thoughts.
It sounds like the game doesn't recognize whatever character is sent when you press the "1" key as a "1".
Here's a quick test that you might want to try: Go to the in-game options menu, then go to the Control config (along the bottom of the screen). Click on "search" (upper-right of the screen) and type "1" using the "1/&" key. What command, if any, is found as bound to that key? The default is "(Multiplayer) Message All" in the Misc list of commands.
Another test to try in Control config: go to the Misc list of key commands, then scroll down to the end of the list, and try binding one of the last few commands in the list (say, Top-Down View or Target Padlock View) to the "1/&" key. After you do that, what character appears in the menu as bound to that command? Is it a "1", or is it something else?
