All,
There was a rogue entry in the database denying the creation of new forms. I have just removed the entry so forms can be created once again. Sorry for the inconvenience!
The problem crops up in extremely rare instances when form creation transactions take a bit more time to complete than expected. It would seem we reached such a case. The result is the inability to create new forms in the database. These symptoms are easily fixed and I'm looking at ways to minimize the extremely rare case to "never".