I reached this thread because I had the same problem: there were no way to receive OSC messages in PDparty. I was sending a simple bang from Isadora, just for test purposes, and it works fine on PD on my Mac (sending to locahost), but does not work sending to my Iphone IP. I was sure that the OSC were issued corrected, cause I can see them on Isadora OSC monitor.
Finally I found the problem was a conflict between the OSC incoming port in PDparty (Iphone) and de OSC port that the patch is lisent to (specified in a message to netreceive). If this one (in netreceive) is the same that the one in Port incoming (PDparty), you get in the console this error "error: blind: Address already in use (48), and the patch in PDparty do not receive OSC messages. I changed the OSC incoming port in PD settings, and the patch is receiving OSC messages to the port specified in [lisent] and [netreceive].
I attach my test patch (just play the sound file "cascabel" from the bang button or from OSC (send "/toggle1 1" to port 4321 to the IP where PDparty is running).
Hope it is useful for somebody. I was stuck for hours finding the reason for no receiving OSC