Unwanted hairlines around graphics in pdfs created by FM11

[Robert CH Shell]

Dear Framers:
I am stuck once more.
I am printing a single file to pdf via the .ps route.
However, I am finding that each and every graphic (all jpgs below 250kb) is
surrounded by a thin white INDELIBLE HAIRLINE.
No hairlines are visible in FM 11
I cannot find the answer in the manual or the lists.
A few Google hits suggest that it occurs in the flattening process but not
specific to FM
I am quite certain it is in the print settings, but I have become dizzy
changing them. 

I am printing using the Smallest File Size option

Rob
PC
8 Gbyte
3 terrabyte drives
Windows 7 
64 bit
TCS 4
Creative suite CS4
Flash Professional