On my XPS M1210 the headphone only work in one of the two plugs at the front of the machine (in the left one to be precise).

In Sound properties I have three icons, two for Speakers and one for Digital Output Device.

When listen to sounds from the laptop speakers the top one is marked as working and the second as Not Plugged In.

If I plug the headphone jack in the left plug, nothing changes but the sound then comes from the headphones. Good

If I plug the headphones on the right socket, also the second Icon becomes marked as working but the sound doesn't come out from either the speakers or the headphones.

How do i get to listen to audio from both sockets?

Thank you