Instead of showing the document properties, my Word 2007 was showing nice “The Document Information Panel was unable to load” message when I was invoking Prepare > Properties. Finally I got tired of this and decided to do something about it. Found two solutions on the Internet.
One was to disable System Event Notification service, and, of course, it was not working (I would wonder if it would, as I do not see any link between SENS and document properties).
The other one was a bit more elaborate. It argued, that the missing “%ProgramFiles%\Microsoft Office\Office12\1033\ipedintl.dll” is causing the issue, and copying this file into the abovementioned location would restore Word’s functionality. The file was missing in my case; I found it in “%ProgramFiles%\Microsoft Web Designer Tools\Office12\1033\”, copied it over to “%ProgramFiles%\Microsoft Office\Office12\1033\”, and voilaz, Word now shows the document properties panel fine.
UPDATE I had to reinstall my PC. So, fresh Windows XP SP3 and fresh Office 2007 with SP1 – same problem appeared straight after the installation :) . Really sucks (but at least now I knew how to fix it!)
UPDATE 2 I had to reinstall my work PC now, and again the same shit, except now I used Office 2007 Ultimate SP1. But now there was a twist – ipedintl.dll was nowhere on the hard disk… I found it on Office installation disk in the “\Office.en-us\OfficeLR.cab” file (.cab is an archive file, like .zip or .7z or similar). It is called IPEDINTL.DLL_1033, and you should extract it to the above mentioned “%ProgramFiles%\Microsoft Office\Office12\1033\” directory (using e.g. 7-zip) and rename it to ipedintl.dll. Problem fixed.