Sincere thanks to everyone who's responded to this, and particularly Baruch and Philippe, who got there just ahead of me.
Eliminate one thing at a time... The only unusual thing about this file for me is that it uses a new - to this site - font, Sabon. I purchased Sabon MT from fonts.com as a PostScript Type 1 and installed it in Classic as normal. Changing all the Sabon in the test file to Times causes the file to distill as expected. I tried this again with Officina Serif, and the same results. Sabon MT is a brand new font, so no possibility of corruption, surely? I will take this up with Monotype support, but if anyone has an idea as to what might be happening I'd be glad to hear. I have never seen this problem caused by a font in, oh, er... eighteen years of using FrameMaker. Philippe: I don't have the option of using another font, sadly - the designs are dictated by the publishers. -- Steve