UNO+android+bluetooth+pfod connect problem

I have a really mysterious problem. With a pfod sketch UNO sends messages to configure android device. There is handshaking between them. I get a timeout disconnect first message attempt.

If i try this with a new board and test sketch it works. However if I then load in another sketch and later come back to the test sketch it no longer works. I have tried this with three boards. This phenomenum also exists if I try other control apps, so its not a pfod flaw. Plain serial terminals work fine. Could it be that my other sketch leaves something behind? Any ideas appreciated.