I initially paired the SMH10 with the Zumo GPS and it works fine. Then I paired my iPhone to the SMH10 and it works fine. When I turn on my GPS after pairing with the iphone the SMH10 will not give driving instructions. If I pair the GPS first then the iphone will not pair up with the SHM10. I suspect I did something wrong so a little help from the smh10 support tram would be appreciated.