Thanks Wolf for the Trackir tip. It works now.
@Russkly
You can disable (or change) the screenshot key by right clicking on the steam icon on the taskbar and selecting SETTINGS. Once there, click the IN-GAME tab and there you'll have the option to either delete or replace the screenshot setting.
In the near future, however, once trackir updates their game list to include CoD, you'll be able to make a better profile (as opposed to the default one, which is a bit too slow for my taste), and make your own shortcut keys. I normally use /*- on the keypad, since they're usually not mapped to anything in games.