PDF Question

[chemistry_geek]

Why do some Adobe PDF files not open in Preview? I've noticed problems every once in a while where a PDF file was generated by Adobe products, and in another case, my taxes from Turbotax.com. A paper accepted for publication that my advisor sent me related to my masters thesis and generated by Adobe Acrobat could not be opened in Preview. My taxes from Turbotax.com also could not be opened in Preview. When these documents were opened in Adobe Acrobat Reader and printed as (saved as) PDF documents again, then Preview could display them. What is or could be the source of the problem?

Also, when these Adobe generated PDF files are viewed in Adobe Acrobat Reader, scrolling is painfully slow. When the PDF files are re-saved so Preview can display them, scrolling is still painfully slow. When I generate my own PDF files within OS X apps, scrolling is fast. What might be the source for that annoying feature?

[RacerX]

Adobe's Acrobat PDFs change with each new version, so that PDFs made in Acrobat 5 are not readable in Acrobat Reader 4 (forcing you to get a newer version). The Display PDF engine (what Preview uses) is bases on about the same version of PDF that Acrobat 4 would product. I work hard to make sure that all my PDFs are either Acrobat 3 or Acrobat 4 readable (the latest PDF readers for Rhapsody/Mac OS X Server 1.x can only handle version 3 or earlier).

This is one of those examples were Adobe is copying Microsoft's business practices.

[chemistry_geek]

Thank you RacerX