Sound mute after use of headphone

[wobo]

Beta 3 - sound is working fine with all applications (currently using kaffeine with DVB-T adapter).

Plugging in headphones, sound is still fine but internal speakers are mute, like intended.
Plugging out headphones, no sound, internal speakers are mute.

PA sound control shows everything ok, application tab shows kaffeine playing and the volume bar is moving according to sound signals. kmix main volume is set to master but PCM is also set to 100%.

Rebooting solves the problem until I will use the headphones again!

I never used headphones on this machine but it does not seem to be a hardware issue (switch between headphones and internal speakers works on Ubuntu & Mandriva).