Microsoft has posted a fix for the RMS bug I had written about last week. Here are the links for the fix:
Cannot Open Office 2003 Documents Protected with RMS – Update
The issue of the inability to open Office 2003 documents protected with RMS has now been resolved with a hotfix. You can obtain the hotfix by using the following locations.
Office Client – KB978551
Word Viewer – KB978558
Excel Viewer – KB978557
I hope this helps those who are having this issue.