I had the same problem.
First go to post #6 in this thread:
(thanks once again to worachj)
After doing this, desktop worked fine, for a little while, and then it would drop out and wouldn't work again until I re-booted my PC. Even after doing this, my Tivo boxes wouldn't show my "What's playing on ***PC". And then after a while it would.
The first thing I discovered was that when my PC 'went to sleep' I would lose all connections. I solved this by setting my 'power saver' on the PC to "never sleep" so that it doesn't turn off and the connection is maintained.
For a while after this, the PC still would not show up on one or the other of my Tivo boxes until one day about two weeks ago, everything started working and it has been performing excellently since. I don't know what happened, but I am currently thrilled.