CRT/LCD

When I hook up an LCD projector to my Dell Latitude 610 laptop the
application I am running Excel, Powerpoint, Word, etc goes into a very large
magnification mode and I cannot get it to function properly. In fact I don't
have to hook up my projector. I can start up and Excel worksheet and press
the Fn and F8 keys at the same time and the magnification of teh spredsheet
goes to 400%. When I ask Excel to go to 100% it does but immediatly blow back
up to 400%. I hope someone know what do do here.