Edit Profile 'Custom Field' showing unexpectedly and can't be permanently removed

Edit Profile 'Custom Field' showing unexpectedly and can't be permanently removed

I click on Edit Profile for a user (I want to update some details) and notice that an "Alias" exists as a customer field:

http://www.translution.com/public/resources/4zohoforums/WhereDidDavidComeFrom01.png


So, I click the red cross to delete "Alias" 'David' that has appeared from nowhere (it is my first name!).

Thus:
http://www.translution.com/public/resources/4zohoforums/AliasDavidTogo.png



This gives me hope (it appears to be gone):

http://www.translution.com/public/resources/4zohoforums/ReadyToClickOkay.png



BUT when I click OKAY its comes back!

http://www.translution.com/public/resources/4zohoforums/DavidBackAgain.png


Please advise.

David