Originally Posted by MissStress

It looks like the display button on your laptop might be F2.. is there a picture of what looks like a monitor on it? If so, next time your machine does the split screen thingy, hold the Fn Key (bottom row, second from left.. in between the Ctrl key and the Windows key) and while holding it, press the F key that has a picture of the monitor. You may have to do this 3 times, it will probably turn your monitor black the first couple times.
What this does is make your notebook 'seek' for different display devices (external monitor, projector etc..) and when it does this it sets the resolution to the correct setting.
A silly work around but better than rebooting. I will see if I can find a better fix but from my days as a tech, I remember coming across this a few times on XP notebooks.