i meant that the 2.5mm jack doesn't take a "standard" 2.5 headset. it only works with specific headsets made for the phone. i made a 2.5mm to 3.5mm adapter for mine with a resistor and some parts from an old headset since it won't take a straight up 2.5 to 3.5 adapter for music. supposedly the moto rokr 2.5mm to 3.5mm works for music.
but anyway the e61 has pop port instead of a 2.5 jack, and the e62's 2.5 jack is not standard it is proprietary.