screensaver activates despite keyboard activity

[Irishpolyglot]

Hi all! This is a minor problem, but still quite annoying. I'm working, which just involves writing documents (in a special application that needs Windows, i.e. within virtualbox and doesn't work with in Wine). I've set the screensaver to come on after 10 minutes of inactivity... but it always comes on after 10 minutes of me typing! "Inactivity" seems to only mean lack of mouse activity, or maybe typing within virtualbox isn't registered?
Other than disabling the screensaver (or extending the time), is there any way that my screen won't fade away as I'm typing?
Thanks

[P4man]

I think you answered it yourself: keystrokes in virtualbox are probably not picked up by gnome, so it considers you inactive. Not too sure what (if anything) you can do about that, other than obviously disabling screensavers..