Heya, I get that same problem....

Currently, I'm using an older AGP ATI Radeon 1600Pro 128mb card. And my drivers are only a couple months old from the latest release. I suspect it might be an ATI driver issue.

Earlier this year, prior to falltime, I was using an nVidia Geforce 7900GS 256mb PCI-E video card. I never had that problem ever, with the current nforce drivers at the time. Unfortunately the card went up in smoke and I got a replacement PCI-E 2.0 spec 8600 card that I can't use in this older Asrock AGP/PCI-E combo board. Hence reverting to the older 1600Pro until I can make a system upgrade.

By the same token, I also sometimes get a blank assembly room, and I mean everything totally blanks out from the view. Sometimes I can get it to "flicker" back by using the camera pan controls, sometimes it sticks and sometimes it blinks out again.

On the odd and very annoying occasion, I'd get an "Error: Rendering Failed" type message in the assembly room window, and usually Carrara freezes up...

Using Carrara 6.2.1 , XP Pro, Q6600 cpu on an Asrock 4coredual-vista board, 2gb ddr ram, ATI Radeon 1600Pro...

And I've also got a shiny new 8800 in the box I can't use on this board either. I really need a better motherboard and more ddr2 or ddr3 ram.... (that 2gb is really limiting what I can render in a scene!)