Argh...usual lack of sound problem on headphones

[Tallangel]

My headphones worked fine on Sunday. On Monday morning they didn't. Tried them on another device and they worked fine. Tried another set of headphones on iphone and they worked the same as the first pair. Music works ok whether in music file or in podcast. Recorded voices in podcasts and telephone calls don't provide any sound through the headphones even though all sound works find on the speaker and speakerphone of the iphone. Tried cleaning the headphone jack, no results. Tried restoring, no results. Tried uninstalling Fring (voip client) no result. HELP!