The initial fix was to ensure that the colour graphics were in RGB not CMYK. THis appears to mean that lyx can deal with the image conversion.
If i view in dvi then the file and graphics are processed correctly.
If however i choose any of the view pdf options including dvipdfm then i get a page error telling me thats the file cannot be displayed. In pdflatex it doesnt give an error, just doesnt display any graphics at all.
Any advice. This document is being sent off to a publisher who may or may not need the pdf files. I cant assume that dvi will be fine for them.
Geoff
