I have followed the installation instructions to the letter; have used the FileOpen installer, and also done manual install. The Finder shows that the plugin is "ticked off," when getting info about Adobe Reader 8 (each time I close the info window, Finder quits though - dunno why). Anyhow, Adobe Reader does not list the plugin, when selecting info about plugins, and subsequently is unable to open the DRM protected pdfs.

I have checked file permissions, run DiskWarrior, deleted Finder preference files, and the whole package - short of doing a system re-install. Hardware = MacBook Pro Core2Duo, system = 10.5.

Suggestions welcome.

Jorgen,
A couple of questions:

1. Did you use the FileOpenMacInstall.dmg file from our (nr.com) website, following the link above, or did you get it directly from the FileOpen website (not recommended)?
2. What is your exact version of Adobe Reader, hopefully 8.1.1?

Are there any other users out there who have had trouble with MacOS 10.5 (Leopard)? That is the only difference I can see between Jorgen's configuration and hundreds of others that work fine. Right now, about 80% of Mac users are still using 10.4 (Tiger).

Yes, I used the FileOpen downloaded from this web site. When running the installer I get the error message "No Acrobat Reader found. Please install ... manually." I next followed instructions for manual installation (installing the folder for Reader 8.0); Adobe Reader is version 8.1.1. The plug-in is still shown in the Get Info window in Finder, but not recognized by Adobe Reader.

This time the whole system went down though, which may indicate the problem is more fundamental, and specific to this Mac. I'll get back with more info as soon as I get the chance to figure it out.

The problem turned out to be with the Adobe Reader preference files. I went to ~/Library/Preferences/ and removed the folder 'Acrobat' as well as the com.adobe.* files. I didn't bother trying to identify which of these created the problem. The app recognized the plugin next time it was launched.

Thanks, Jorgen! This will be helpful to other users. I'm moving these messages to their own thread to make them easier to find.