Unable to write @ in Microsoft Office

For a while, I’ve been having an issue, which only occurred when I was using a computer using Norwegian Keyboard Layout (the only other keyboard layout I use with any kind of regularity is English US), which was that I was unable to write the character @. I investigated it, and realized that the error occurred whenever I tried to use the third option on any key, while pressing Ctrl+Alt. If I used AltGr, the character would appear normally.
 
Now, why this is so, I do not know, and frankly, I do not much care. I would classify it as a minor bug in Microsoft Office, and whatever other software where the same error is encountered. I do know that I have encountered it on both Microsoft Office 2007, and Microsoft Office 2010.