Outlook 2007 sp3 with Exchange server 2007 on Windows 7 64bit.
One of our users has created a handful of categories which she uses on both emails in her inbox and subfolders thereof and in her calendar. There's perhaps 10 or so categories, all using different colors. Last Thursday she created a new one and ever since then, when she opens Outlook in the morning after having logged off or restarted, ALL of the categorized emails and calendar items are re-categorized as the new category.
For example, she'll have emails categorized as Personal, Work, Family, whatever. In the morning they're all categorized as Drafts (the name of the new category she created).
Based on what I've learned, this makes no sense. If she were somehow accidentally launching Outlook with /cleancategories, her list would be reset but that's not happening. Her categories still exist and she can reapply them, but it just happens again the next morning. If her changes weren't sticking I'd assume there's a problem with her roaming profile or mail profile. She's been using them for a year or so and this only started happening after creating that new category. So I don't believe it's a case of user error either. It would take a lot of effort to accidentally change them all, I'd think.
I did find a few other questions very similar to mine but different enough that I still felt I should post my own.