I Can't Cange My Email Address In Helpdesk

I can't change my email address in the cs-cart helpdesk in My Account/Profile Details, I could change any of the other details if required because the cursor appears in those fields but not in the email field.

Is this some sort of bug or security measure, do I have to contact support or am I missing something here?

Update: I logged on to the cs-cart helpdesk and submitted a ticket and they requested my new email address and then changed it for me so it looks like that is the way to go.