After agonizing about this issue for some time I finally figured why I could not get my wireless bridge setup to work properly with Sonos. Here is a recap of the strange problems I was having:
1. Whichever ZP the bridge was connected to would not play Rhapsody or internet radio, however the other ZPs would be fine
2. The CR would sometimes not "see" whichever ZP was connected to the bridge
3. Whichever ZP was connected to the bridge would not update itself, instead hanging up during the update process
So this weekend I decided to check the wireless bridge settings which I have not touched in about 6 months. I noticed that the bridge was set to fixed IP address. Once I changed this to a dynamic IP address voila! All of the problems I listed above were gone. Now here is the really strange thing. As I said, I have not changed my bridge settings in a long time. Prior to about 1 month ago, my Sonos system was working fine with a fixed IP address assigned to the bridge. Either something changed in the latest version of the Sonos SW or my bridge settings changed which I doubt. Anyway, I am just happy that my beloved music system is up and running again.