I just discovered a huge bug regarding custom menues in WordPress 3.01. If you accidentally name a menu with an existing category name, and then rename the menu, you will end up also renaming the category.
In my case I wanted a menu containing my blog posts about SEO (Sökmotoroptimering in Swedish) so in order to make things simple, I named the menu ”Sökmotoroptimering”. After populating the menu, I realized that it would be confusing in the future and re-named the menu to ”Menu 1” .
Right after this, I tried the first menu object in my new menu (which lead to my main category /sokmotoroptimering/ and got a chock when realizing that I was looking at a 404 page.
I was able to find all my blogposts again, now under the ”menu 1” category, I could rename the category and slug (which also had been changed). However, when doing that, the name of the custom menu was changed back.
It’s a bug no doubt, and I’m happy that I’m at WordCamp Stockholm. I hope somebody can escalate it through the right channels so that we can get it fixed (maybe even as their nightly hack?). It needs more testing of course, it can very well be caused by some plugin conflict, but I’m not prone for testing it. And my biggest question also needs to be solved: What happens when I delete my custom menu?