X-ray is acting weard
 

When I turn on X-ray (shading - x-ray) the objects in the scene some times disappear, like they're 100% transparent instead 50% or what ever they should be. Then the objects
flicker between 50% and 100% transparency as I click and move around the scene. This is quite distracting
I first ran into this problem after I downloaded Maya 8.5 PLE but this happens both in 7.0 and 8.5
Dos any one have any idea what could cause such a problem?

Sounds like it could be a video card problem to me. You might want to make sure you have the latest drivers.

I thought I had all my drivers up to date but I stand corrected, I should have tried that to begin with.
Thanks for the tip