1 st :- Doing calls using headphones the proximity sensor is turned on .
2nd:- when you unplugged your headphones then the proximity sensor is still not working.
3rd:- sometimes the headphones symbol was showing in notification bar when the headphones is unplugged and then you will not hear any sound in loudspeaker.
Above the problem is temporarily fixed by restrtting our device. but after some time we face the same problem.
Please hmd grobal do something.......
Other wise we face a very bad experience from Nokia