I have this happen all of the time during animation. I solve the problem by removing the erroneous frame and that's all I can do. I have been in touch with SM since before the SR1 release and Cazky... I think was his name, was very interested in it, as well as stumped by it. It looks like the same issue that P5 and P7 had (don't know about P6, never bought it). For those who had this occur in the earlier editions of Poser, some of you remember that you didn't need to have geometry behind the camera for this issue to occur, though it was the most reported reason. This is probably the same thing and it will probably get fixed soon. 

My problem seems to occur the most when rendering sky domes. It's easy to work around but I think that SM is working on this diligently and the above mentioned tech was rather concerned and had sent off a report to the program team that day, they just didn't have an answer before SR1. I would bet it will be fixed in SR2. Even though they are aware, send them the report of your bug anyway. It lets them know how wide spread the issue is and what similarities there are between computers experiencing the issue.

 

And, before anyone jumps on it, this occurs whether I use the animation renderer or render to tif's.