Agreed, the stripped down version of CAM (Express?) included with AD Expert is nearly useless.
It is not, however, inherently unstable.
Update your video drivers. If your video card GPU is made by ATI, good luck. Alibre is not the only MCAD software out there that suffers from instability on ATI graphics cards.
There is a patch for .net framework that improved stability on an ATI graphics-equipped laptop that I sometimes use but it still crashes occasionally trying to generate MOPS.
The standard versions of Alibre Design and CAM are pretty tough to beat feature-for-dollar wise, but the FREE CAM included with CAD Expert has too few MOPS enabled to make it a viable alternative for other than casual use.