Weird behaviour of N810

Reflashing the N810 fixed a problem that started happenning to me this week. Headphones only played through the left channel.

After reflashing, stereo audio sounded in a perfect way once again. I've been enjoying it for some hours and... the bug showed up again.

If I move the connector a bit I can make both channels sound OK but a slight movement makes me lose the right channel again.

Playing sound through the external speakers is fine. This is really weird and pretty uncomfortable.

[ADDED about one hour later]

I rebooted the N810 and both channels are back in headphones. Not without problems, because I could not turn it on. I had to let it rest and then it turned on. I hope I am not starting to suffer another bug.