Strange problem with saving as PDF (FM 8.0 only)

[Teasdale, Steven (GE EntSol, Digital Energy)]

I have recently upgraded to FrameMaker 8.0 and am having a strange
problem when saving a book as PDF.
 
When I save the book as PDF, the process continues as usual until the
end of the distilling process (converting the PS file to PDF). At this
point, the Distiller status box reads "Relocating files" and FrameMaker
proceeds to re-open all files in whatever book happens to be open at
this time and save them. That is, even if I have already closed the book
I have saved as PDF and opened another book, then FrameMaker proceed to
open all files in the new book and save them. How can Distiller trigger
the opening of all files in a Frame book, even if the book has no
relation to what is being distilled?
 
The problem did not occur with Frame 7.2 or earlier. Any clues would be
greatly appreciated.
 
FrameMaker version: 8.0p273
Acrobat Distiller version: 7.05
 
Thanks,
Steven Teasdale
GE Multilin