I have a Jabra headset. I got it paired to my iPhone 4 no problem but when I turn the head set off and then try to reconnect later, the phone just spins. It lists the headset, says it is there but will not connect. My workaround is to turn the phone's bluetooth off and then turn it back on again to get it to connect. My old phone never had this problem. When I turned the headset on, it connected.
I have the same type of question. I believe I paired and connected a Plantronics 975 to an iPhone 4 although it did not ask me to enter the device code when it paired it. However, when I go into Settings / General / Bluetooth the circle next to Devices is continually spinning. Is this normal?