Slow printing with scanned PDF's with transparent watermarks

Hi All,

I am trying to understand why printing scanned docs with transparent watermarks (opacity <100%) is adding so much PS addons and taking for ever to print.

Adobe 8.1.1 Pro / HP 4200 (64MB RAM) Latest PS driver

=======================================================

PDF = 1mb
PDF in printer queue 1.5MB
Printing to a HP4200 (64MB RAM) takes 30 seconds to print using Adobe 8.1.1 Pro

=======================================================

PDF+transparent watermark (50% opacity) = 1.38MB
PDF+transparent watermark (50% opacity) in printer queue =6.79MB
Printing to a HP4200 (64MB RAM) takes 30 minutes to print using Adobe 8.1.1 Pro
=======================================================

If I set watermark opacity to 100% its ok, but I need the tranparency. Anyone know why this is occuring and if there is any nice workarounds?

Furthermore ... if I print as image the PDF in the printer queue goes up to 318MB but prints within 40 seconds. So the problem seems be be how the layers are interpreted. Can anyone add anything else to this?

Thanks
Tod