Use VMWARE Fusion, do not use Parallels
I wanted to let you know that I have, I hope, the answer to the problem with garbled graphics in my AutoTRAX installation.
I downloaded and installed an evaluation copy of VMWare Fusion 5.0.1, which is a competitor to Parallels. After installing it I installed AutoTRAX and some of the other programs I normally would have on my Windows system.
AutoTRAX runs very smoothly in all views, including the 3D view. According to the Activity Monitor, VMWare uses about 75% of CPU capacity when AutoTRAX is spinning my 3D model, while Parallels was using 98-110% (!) doing the same thing. So the problem apparently is 3D graphics bandwidth in this emulated environment.
A caveat: I installed the latest 1.11.08, which I am assuming still is using the older 3D package, not OpenGL.
Other caveats are that in doing this I installed a fresh copy of everything - Windows, .NET 4, etc. I also have not installed *everything* that I had on my Parallels VM, such as Microsoft Office, Visio, Silverlight, and others. I suppose some of that might have caused the problem, although none of it was running when the problem occurred.
My intention is to make the full migration to VMWare, and leave Parallels behind. The upgrade cost is reasonable, and I would need to spend the same amount to make the upgrade to the latest Parallels version anyway.
Thanks! And you may find this information helpful for others who might be using Macs to run AutoTRAX.