From Jawbone Forums
This is what worked for me:
Reset the iPhone. Start with the phone powered ON and then PRESS + HOLD both the HOME (on front of phone) and SLEEP (on top of phone) buttons at the same time until the screen flashes blank.
For the ICON: Starting with the Jawbone OFF, press and hold the TALK button (top of device). As you hold the TALK button, power the headset ON and continue to hold TALK button.
Please note: if you’re pairing with an iPhone and you get a message that says “Jawbone Not Paired” or “Headset Not Paired” please press on that message. This will prompt the iPhone to continue with the pairing/connection. The message will say Connected not Paired.