display not filling second monitor

[bike756]

I just got a second monitor for my laptop, an Asus VE245 with a resolution of 1920x1080p. The problem is, the display fits the monitor vertically, but there is still an inch or so of space on the right side of the screen that isn't being used. I adjusted the position with the controls on the monitor, and I got it to line up on the left, but not on the right.

The monitor preferences window shows that the second monitor is set at the proper 1920x1080p resolution.

I'm using Ubuntu 10.04, and the laptop is a lenovo t60P with a resolution of 1680x1050p. I don't know what other information to give, so let me know :)

Thanks!