Thanks for a great plug-in.
The iPhone WordPress app does not behave as it should with this plug-in.
If you only add one category to a user it does not show any categories at all. I have tried doing the same with Microsoft Word blog publishing facility and it works fine, so can only blame the app.
It also does the following:
If you add two categories to a user
uncategorized - Category ID 1
a-new-category - Category ID 3
it will also add category ID 13 (1+3)!!
Again this does not happen in Word