Adjust overscan WITHOUT a second display being used

Hi,

I am one of the poor fools trying to get decent TV output via an GF4
MX440. I have one in my media center pc that I've had for a while
now... I've decided again to try getting rid of the annoying black
surround to anything displayed on my tv... and have the absolute
latest drivers for it (the ones released on April 1st, which made me
nervous!) And while there is now a PAL resolution to choose, and
indeed yes it does remove the black borders, it does so with a LOT of
overscan... I loose so much around the image. So much so that the
desktop becomes unusable, and also it's a bit too much image from my
videos for my liking.

So, I've seen some stuff about using nView and Clone, and how you can
adjust the size of the screen with that, but it always seems to assume
that you have a monitor AND a TV hooked up, whereas I ONLY have a TV
hooked up to the box.

Other than using TVTool (I really refuse to have to PAY for
functionality which should be included with the card to begin with),
is there any way I can reduce the amount of overscan when switched to
the PAL resolution, OR increase the size of the screen to remove the
black borders when displaying 800x600?

Thanks in advance if anyone can help.

Simon