There's still something rotten in the state of Adobe, when it comes to giving proper clues to when and what is needed to get up and running and stay updated with ADPS.
Take this scenario for example: a brand new install of a downloaded InDesign 5.5 trial on a Mac, user-wisely updated to the latest version of ADPS, refuses to preview a folio with MSO's. After double-checking all updates (offering no remedy), the final solution includes the tedious process of de-installing all parts and manually removing all remnants of ADPS. Before we embark on that last option, I check whether the preview error (in Desktop Viewer) is actually lethal, or just a Viewer's problem. It turns out that there's nothing wrong with the folio in the Content Viewer on the iPad ! So the Desktop Viewer seems to be the culprit.
I remove the app from the Adobe folder in Applications, empty the trash, and try to reinstall it with the Producer Tools. But the installer seems to skip the Content Viewer, since none is installed again. Eventually I open up the lousy installer's Payload package and drag the Desktop Viewer app to the proper folder. This works, and all is fine.
Conclusion: the Content Viewer might be outdated but the installer doesn't notice nor correct it. Furthermore, even when it is genuinely missing, an installer still thinks it's there, and doesn't install it.
Another scenario: the Folio panel of a freshly downloaded and installed InDesign 5.5 warns that it should be updated. The user is lead to the Download page of the Producer Tools and installs it. Of course, as you can guess (we're used to this flaw), no luck. She tries it once more (she's used to Adobe installers) but again, no luck. So she goes to my simple three-step overview of downloads, takes another tour at both the Producer Tools and Folio Builder Panel, and presto. I hoped that newer InDesign installations would have corrected the flaw in the Folio panel, but it seems that it is still the same version.
With the dawn of the "next" CS-version (as anyone with eyes and ears can assume), I hope these problems will vanish, and in the meantime I'll try to keep smiling while pointing out these flaws and continue correcting them. But I'll go ballistic when this kind of stuff is still happening with the new version !