Problem with pdf interactive file

Question

In InDesign CS4 I was able to creat an interactive pdf file which I could then send to my iPad. I have several such file on my iPad that can be read by iBooks or GoodReader. However, when I try the same thing with InDesign CS5, most of the graphics fail to show up. Out of 46 graphics, 1 psd and 16 of 43 jpgs showed up. Two pdfs and the rest of the jpgs left a blank hole on the pages.
If I export a print pdf file, which is much, much larger, my iPad can read it.
Also, I tried exporting the CS5 file as an idlm, opening it in CS4, when exporting it as interactive pdf. That worked. But it seems like a complicated way to do things.
Why doesn't InDesign CS5 export iPad-readable files that include all the graphics?

Answer 1

The file was made in CS5, based on a template from CS4.
It is true that a file exported to pdf print will open properly on my iPad. I have past files made in CS4 that were interactive such that a reader could click on an item in the Table of Contents a go directly to that article. I could also fix it so that clicking on, say, the title of the article took the reader back to the Table of Contents.
Exporting a CS5 file to pdf print seems to lose any of that navigation capability, understandably.
What really puzzles me is that something that was rather straightforward in CS4 seems very complicated in CS5. By going to CS5 I am giving up the capability to export an interactive file that will appear on and work properly on my iPad.
I don't understand what it is about certain graphics in a CS5 document that show up in Preview or Acrobat, but don't show up in iBook or GoodReader on my iPad. I had no trouble with CS4 files, but I sure do with CS5 files.