David has alerted me (with some frustration) to a problem associated with the image-resize feature of the upload process. Contributors, for now, please do not use the image-resize / thumbnail feature as you assemble your posts. I think this problem is likely related to the spurious error messages seen on rebuilds but the files are not being processed, unlike the case with the rebuild problem. This particular issue is also related to an aspect of the new fast CGI implementation. I will be looking in to these problems as time allows but do not have a resolution timeframe.