Help with resolutions and projectors

Hey guys. I work for a college and we have a teacher that is having trouble with his resolution on his mac in a classroom.

When he is using mirrored settings for the projectors, it changes his reslolution to a really low setting even though it is displayed as the normal resolution. The weird thing is that every setting is the same for both mine and his profiles and I don't have the problem.

Is there a way to clear his preferences for the screen settings?

I'm not very tech minded when it comes to Macs as I work with IT on the windows systems, but our Mac technician is no longer with us so I'm having to solve some of the problems.

Any help would be appriciated.

You could try resetting the PRAM (instructions here).

How is the Mac connected to the projector? Having used projectors in classrooms, I know that the setup can be quite elaborate sometimes.

Thanks. I'll try that later.

It's set up with a minidisplay port to vga connector with a vga cable into a wall plug which then feeds up the wall and into the projector. Not that complex.