There isnt a Nokia 3610i. Do you mean 6310i? If you do i think it is in connenctivity on the menu. Or have a look at www.nokia.co.uk which will give you all the answers
had same problem with a razr and motorola bluetooth. check in your headset manual mine had to put in to a mode for detection ie hold down the on button until flashing light turned to steady light then search with phone.