PDF Import and Associated Print Resolution

We are setting up our internal system to include printable part drawings directly from Fm. The PDF's are exported in sufficient resolution in ProE to allow readable resolution on lines and dimensions when printed in A4 format. However once we import these pdf's into Fm (6.0 on OS10.2.4), the print resolution in greatly reduced. From my previous experience with Fm when importing pictures the resolution is pretty much imported the same as the original, but in the case of pdf's, it seems to have degraded significantly, such that the same pdf printed directly to A4 is no longer legible when printed from Fm. We have the graphics field set to enlarge/reduce, and have insured the field size just fits within a preset A4 page size at 100%. My dilemma is the pdf format is the most flexible for us to use across all platforms and customers, I very much want to stay in this format for standard export from ProE, without requiring multiple exports of thousands of part drawings in different formats for differnt apps. Any insight on how to maintain the original pdf resolution would be appreciated.

Rod