I'm more than a little irritated with Carrara's programmers, and I wanted to post a warning to everyone considering buying or upgrading -- in hopes that this will prompt them to fix the problem.  

Carrara 8 pro 64 bit does not work -- at all -- on my system.  It crashes instantly on launch.  
I have uninstalled and reinstalled multiple times.
I have all the latest drivers and have tried every troubleshooting method under the sun.  

Other high end graphics software works fine on my system (Zbrush, Poser 2010, Blender,  Hexagon 2.5, GIMP) so it's not a failure of my hardware.   And after consulting repeatedly with their techs, their only response basically was to shrug and say "sorry".   They just can't or won't find and fix the bug.    Apparently I'm in the minority, and since it works for most other users, it just sucks for me.     If you have a system with similar hardware components, be forewarned not to expect results:

My System:  Asus mother board.  Windows 7 64 bit Home --  Intel(R) 3.0 Ghz Core(TM)2 Quad CPU -- 8 GB  RAM --  My Graphics Card is an NVIDIA Geoforce GTS 250.
Nothing in my system is particularly exotic or unusual -- 99% of the software I run on it works flawlessly.  There's no good reason why Carrara should be any different.

Don't misunderstand -- I like Carrara and want to use it.

I'm just very frustrated that they have written code that is apparently just not compatible with certain hardware or operating systems (or some combination thereof).  One sign that really tells me they haven't coded everything cleanly is that their uninstaller clearly doesn't really thoroughly uninstall old versions of the program -- not that this is the whole problem, but it is a bad sign that they haven't carefully engineered a clean product.

Carrara coders, please, please, please fix your product up and test it better on multiple hardware configurations before selling it.   And fix it now for those of us out in the cold.