Help! HiRes PDF export inverts bitmap graphics

[StephanP]

Hi,

I'm having a major problem with the 20-page brochure I'm now trying to get ready for the printer.
When I do the export to PDF/X (300DPI, no compression) then bitmap graphics get inverted in color. (See attached screen capture from Acrobat 8)

Has anyone come across this problem, and more importantly, does anyone know ho to solve this?

I'm currently working with XXP 3.24

Stephan