I removed my Media Center usb items before going into the game and voila, it worked. If that didn't work, i would guess it is some other problem having to do with the keyboard.
Try some of the following keys:
The key next to Z (on the left of Z), on a US keyboard its marked |\, try pressing CTRL and SHIFT when pressing the keys.
The key next to the right shift marked ?/
the keys next to enter on the left marked @' and #~
One of these will be mapped to the tilde key in Italian, sorry I can't be of more help, but I've never used Italian.
Best thing to do: Open notepad and press the keys, using shift and control as well until it puts a tilde on the page, then remember what you pressed for FO3.
what you means "Open notepad and press the keys, using shift and control as well until it puts a tilde on the page, then remember what you pressed for FO3."
Pressing SHIFT and CONTROL means you'll get all the available options, such as the key next to 1, normal is `, shift is ¬ and ctrl is nothing on a UK keyboard.
So open notepad and press the keys that are associated with the tilde (this is a tilde ~ and is what you're looking for) until you find it. Then when you're ingame, just press whatever combination of keys made that mark.