[AUCTeX] preview-document error only when run on included file

[Dan Maftei]

I have a master file which \includes other files. These other files set the TeX-master variable through a local variables comment at the end of the file. From within these files, I can run C-c C-p C-b and the previews work. From the master file, I can run C-c C-p C-d and previews in all included files work. However, running C-c C-p C-d from one of the included files does not work: I get the error symbol for every preview, with the error "/typecheck in --setfileposition--"

I cannot get a MWE working. So I presume this is due to something complex I am doing. My included files are very simple, just sections and subsections. My master file, however, uses the pdfpages package and includes a PDF file (as the title page, should it matter). Otherwise, I am not doing anything fancy. I am using the report class. 

Any ideas what could be causing this?

Dan