Same thing is happening to me only I've got Carrara 5 Pro and it's happening when I render.

I've cleared unused objects and shaders, checked the poly count which was under 200,000. The objects in the image render fine separately and image size is the same I've been using.

I've got 2G Ram ,dual core Athlon processor and the video card has 512MB , so it's not something beyond the capabilities of my machine.

And as if that isn't enough, mapped textures are disappearing when I save the file and reopen it.

I definitely would appreciate if anyone has any ideas on what is going on because I haven't changed a thing.