Both Ronstuff, and Raven, Thank you for answering! And both of you were right, it seems to be the bias settings. Changing them down to 0.3 solved the problem. Thanks again for your help: I was really stumped, and P5 would have been useless to me with shadows like that! :-) On a related problem o.8 seems to be the default bias setting for me. Is there any way to change these defaults without having to do it to each lightset one by one by hand?