Monitor hooked to laptop acting funky

Thanatos

So I'm setting up a laptop for someone that's hooked to an external monitor running in extended desktop mode. When the laptop restarts, the monitor decides that the screen size should be the same as the laptop, so it ceases filling the entire screen until I go into the display settings, adjust the resolution until it overfills the screen, then readjust it back down to where it was before. It only allows me to use one refresh rate. Already tried updating both the video and monitor drivers; monitor doesn't have drivers, video drivers are up to date. Any ideas?

This is a new Dell laptop running Windows XP pro, and a Westinghouse monitor.