Computer details.

Okay I stopped my Raspberry Pi and made an Image of The SD Card ( i.e. the system ). I then wrote it to a new card, the idea to prepare for a new Raspberry Pi. On the new image I changed the hostname. In doing all of this I forgot to suspend Einstein@home. Now if I check my Computers the results for my Pi now have the hostname of the new machine, How do I fix this so that I end up with two machines being reported. I assume that taking an image meant the computer ID got copied. Do I have to do an un-install and reinstall on one of the machines?