Tennis elbow seems like one of those things that's tough to get rid of. Rip says he rehabbed his using chins... you might search around for where he talks about that. There have been quite a few recent threads here on the subject as well.
I've had mine since around February or so ... when I was at 3 sets of 13 at bodyweight chins and also doing weighted chins on another day of the week. I'm up to 5 sets of 8 now but I've still got the tennis elbow.
Also, search/read up on the Ibuprofen protocol.