Layout Tab Failure

[SouthernDrafter]

Okay folks, gotta real head scratcher for someone. When my supervisor goes into this particular set of plans (a drawing), when he clicks on a different tab, including the model tab, the only thing that happens is that tab box is highlighted (turns black). That's it...nothing else happens. This does not happen when I bring up the drawing on my comp. I've seen some doozies over my years, but this one really trips me out.

Anyone know what could cause this? I'm assuming some kind of variable settings, since AutoCad seems to have some 1,000,000,0000...etc. variables these days.

 

[SouthernDrafter]

I should add that I didn't draw the original drawing, I've just taken it over after an employee left. I am using 2002. My supervisor brought the drawing on his comp in both 2002 and 2004. Same thing. The tabs highlight but take no action. If he clicks every tab, then everyone highlights....
really creepy!

 

[IFRs]

It sounds like his Ctrl key is stuck down