This does not sound like an error from EXPORTING to PDF since there is absolutely no involvement of Distiller in the export process.

What's the OS? Is your user perhaps trying to PRINT to Adobe PDF?

Most users encounter no errors at all with Windows 7 and CS5.5, and I've never heard of anything like this at all with an export. Do you have any third-party plugins installed?

Also, try repalcing the prefernces and see if you can export successfully. See Replace Your Preferences

There are literally dozens of companies that sell add-on plugins to do things that ID can't do out of the box. Newspapers, for example, will often have plugins to help with automating content placement. It won't be definitive, because not all vendors install through the Extensions Manager, but if you go to Help > Extensions Manager... you'll get a list of plugins that are installed, along with the author name. Anything that doesn't say Adobe Systems is suspect. You can disable those and test.

There was a bug in the 7.5.0 release (fixed in 7.5.1) that allowed incomaptible version 7.0 plugins to load, so tyhat's one potential source of the problem. Many large organizations also have centralized font management, and font managers, some versions of Suitcase in particular, frequently show up here in the forum associated with problems like crashing. Updating the font manager is usually indicated when switching to 7.5.

And of course some fonts are just plain wonky and can cause trouble (these tend to be free or cheap fonts from unknown vendors, but there's no absolutes here either). ID is very sensitive to font problems, and seems to get more so with each version.

No special steps (unless you count copying the font into one of the private fonts folders rather than installing as a system font so all programs can use it). ID sees fonts in the system fonts folder (installed using whatever the current install protocol is, which for Windows 7 seems to be right-click and choose install font, or installed by your font manager), or fonts that you copy into ..\Common Files\Adobe\Fonts or ..\Indesign[version #]\fonts.

I'm going to speculate that some oject on a page may be responsible, and further that it might be a placed .eps file, but I really don't pretend to understand postscript errors.  I'm basing this speculation on the failure to both export and to print to .ps, which suggests a problem with a page item rather than with code ID is producing.