I am guessing you have upgraded your OS to Windows 7 which is why your fully paid version of Deskscapes is of no use.
An upgrade to Deskscapes 3 is only $8.95 and is not repurchasing the same program, it is purchasing a number of major updates including the ability to work in Windows 7 (an OS that did not exist when you purchased Deskscapes)
As for transfering the ownership, I am afraid I do not know the answer to that question. Assuming they are on your account it would be something sales@stardock.com would have to help with if you wished to transfer them to another SD.net account instead.