Gilles,
I don't have the SM10 but do have the SMH10 and have paired it to other devices. A couple times I had forgotten to do step three, this step tells the SMH10 to complete the pairing. If you don't do step 3 it just sits there blinking blue.

IIRC for pairing the SMH10 with anything;

1;Put the SMH10 into pairing mode. (blinking red)
2;Put the other device in pairing mode, (SM10, blinking blue)
3;SMH10 blinks blue (ready for pairing), tap the jog dial on SMH10 to pair.

 

Thank you John. I got a reply from Sena and I was mixing steps.
To pair the head sets you just press on the jog dials for 5 seconds, but to pair with another type of device you have to press on the phone button on the back of the jog dial, then the fast flashing red/blue tells you that you are in pairing mode.
Instructions below; they may help someone else in my situation...

Hello Gilles,
We can try to go through the steps remotely to hopefully get you up to speed.
I recommend starting with a fault reset on both headsets:
Reset by pushing the pin-hole reset button at the back of the headset main unit. Insert a paper clip into the reset pinhole and press the reset button for a second with light pressure. The SMH10 will be switched off, and you have to turn the system back on and try again.
First, lets pair the 1st SMH10 to the SM10:
1. Turn on the Bluetooth headset by pressing the small phone button at the back and the big round jog dial together for 1-2secs until the blue LED come on and thereafter the red LED will briefly flash indicating the charge level (1-4 times) then it will go back to blue LED.
2. Place the Bluetooth headset in phone pairing mode by pressing the small phone button (not jog dial) down for 5secs until the LED rapidly flashes red and blue.
3. Turn on the SM10.
4. Press the Pairing Button on the SM10 for 5 seconds until the Blue LED is rapidly flashing, the Red LED will be on.
5. The SM10 will detect the Bluetooth headset nearby and connection will be made accordingly.
6. If the first headset is connected, the Blue LED will slowly flash.
Now we are ready to pair the second SMH10 headset to the SM10:
1. Turn on the second Bluetooth headset. (Refer above)
2. Place the second Bluetooth headset in pairing mode (Refer above)
3. Press the Pairing Button for 9 seconds until the Red LED is rapidly flashing, it is important not to stop pressing down even when it starts flashing blue. Please make sure you keep holding the button down until the RED LED flashes rapidly.
4. The SM10 will detect the Bluetooth headset nearby and connection will be made accordingly.
5. If the second headset is connected, the Red LED will slowly flash.
Let me know know how all that goes.
Thank you,
Anastassia Tolpygo
Technical Support Engineer
Sena Technologies, Inc