First of all, are categories supported at all, i.e. are one or more categories already available by default? Are you using pdaXrom, pdaXII or weexpc?
Varti
pdaXii1313v2 build5.5.0-alpha5 Alice
I have default categories: Office, Internet, Sound, Graphics, games, Other, System Tools, Utilities.
I want add for example, Emulators and Development