I have 2 pdf's i'm running through CFPDF action="thumbnail". The first pdf returns a perfect looking thumb. The second returns a thumb with only the text and background colors, but NO background or foreground images. I didn't create these PDF's, I can't tell a difference in the two.
Here's the code, simplified for testing purposes:
<cfpdf action="thumbnail" source="First.pdf" destination="thumbnails" overwrite="yes">
<cfpdf action="thumbnail" source="Second.pdf" destination="thumbnails" overwrite="yes">
<img src="thumbnails/First_page_1.jpg">
<img src="thumbnails/Second_page_1.jpg">
I can send the pdfs in question if necessary, but would rather not post them here for obvious reasons.