I’ve had mixed results.
1. Snow Leopard: 8.1 & 8.5 - After awhile 8.5 (any version) using both on the same HD seems to corrupt my content browser in 8.1. Items dragged from the browser don’t show up in the canvas. Perhaps just my imagination but when I delete 8.5 and don’t use it this problem goes away. Its happend before that is why I suspect 8.5 as the culprit. Solution: Removed 8.5
2. Lion and Mtn Lion 8.1 & 8.5 - 8.1 crashes almost immediately after opening and using it. Success at installing 8.1 rendernode and getting it to work as a node only. All versions of 8.5 seem to run stable but I get the white screen preview issue too - but only some files, it seems to work okay with low poly scenes. Solution: For Mtn Lion and Lion use 8.5 not 8.1
3. Since I have multiple Macs for animation projects, I use different drives with different OS’s and versions of Carrara and that seems to work. I partitioned the HD on my Mac Minis that came preinstalled with Mtn Lion and they run Snow Leopard using a copied cloned HD without problems. Copying your content library to an external HD you can use your content on any machine and save disk space. From my testing, Carrara seems to run best using a SSD with 16GB of RAM.
Personally I just prefer Snow Leopard, as I see very little difference between Lion and Mtn Lion and I can still use my PPC software. I have a Powerbook G4 with OS 9 to run some legacy apps that I use now and then. (FYI: it takes 45 minutes to render a Carrara file on my G4 that takes my Macbook Pro 2 minutes to complete!)
So with creative workarounds, don’t let these “Daz” or “Apple” issues slow you down!