help with display resolution?

Ok, for about three weeks, i have been playing with the beagleboard,
and trying very hard to get a ubuntu with gui image running
correctly.

I finally got an image up and running, and am actually posting from it
right now. I have one major issue though, and it is very very
annoying.

Apparently something is wacky with my display resolution. I am using
a widescreen acer monitor, al2016w, and the installation of xubuntu is
saying that it is displaying a resolution of 1280x720.

I am only able to view about 80% of my desktop. The entire right side
is missing, I can't see any of the tray icons, time, wireless network.
etc.

It appears to me to be a resolution of about 800x600.

How can i correct this? I am totally lost, and have searched and
tried a couple of different things, and none of them have worked.

Any help would be appreciated.

thanks