I'm getting the following error when trying to create a new folder:
A folder with the name "foldername" already exists.
I get the error from the webgui using Firefox 3.0.1 (latest), Thunderbird (latest), and even tried Outlook Express 6.x just for the heck of it. None of them display the foldername, but shows all other folders.

The error comes up when trying to create foldername in at the "root" level (same level as Inbox, Sent, and all my other folders). I remember trying to create that foldername a while ago and got some error. The foldername doesn't display in any of the above mail client tools and browsers.

How can I get a list of folders of that account? (there might be other hidden folders that still exists.) And how can I delete it, so I can recreate it so that it will show up?

ZCS Community Edition 5.0.7.