Renaming Uncategorized creates duplicate Drafts/Posts

I have come across a strange issue that is really frustrating my bloggers.

I renamed the “Uncategorized” category to “Updates” and now I am getting a duplicate post created whenever I add a custom field to a posts during editing.

The scenario is this:

I start a New post. I add a title and a body (the post is autosaved as a draft while I am writing)

I now go straight down the page to Custom Fields and add a custom field. I click ADD CUSTOM FIELD to save the field.

I save the post (not publish) and look at Manage Posts page – there are TWO posts of the same name.

If I hit Publish instead of Save then I get one published post and one saved draft. (In the category column, one of the two posts one is shown as UPDATES (and is a clickbale link) and the other is shown as ‘Uncategorized’ and is not clickable.)

I can stop this happening by clicking SAVE before adding a custom field but never had to before.

I tried renaming the ‘Uncategorized’ category back to Uncategorized but the same thing is still happening with the categories in the category column in the Manage Posts page both showing ‘Uncategorized’ but one is a blue clickbale link and the other just a black text – non link.

I have reproduced this on mupltiple sites. As soon as I rename the Uncategorized category it starts happening – and there seems to be no way to go back.

HELP!