Looks like Mr. Grant registered the domain twisted-melon.com in 2002 so regardless of whether he moved to protect (by legal means) himself from another "squatter" in 2006, he appears to have been using the name in some form or another since 2002.

Hmmm....

Edit:

I also see that you register your domain in 2000, but as you said you didn't start using it as your trademark until 2004.

I think you made a poor choice of name, you chose a phrase that in some form or other could be attributed to at least 2 famous people, one particularly in the UK (where Jay Grant resides).

I'm with the other guys on this, I'd be pissed if you came along and tried to take my twitter or Facebook page away. I think you need to chalk this up to experience tbh.