I installed Ubuntu 11.10 recently, and sound doesn't work properly. Whenever I try to play a sound (from any software), the sound is muted, and when I unmute it, it stats there for a fraction of second and mutes itself. After trying various things, I plugged in a headphone in the front microphone jack of my computer, and magecally, the sound started to come out from my speakers (Which are connected to the line-out in the rear panel). I have analog stereo speakers. The sound card (intel HDA as shown in alsamixer) is detected properly. I have ecs G41T-M7 motherboard and nVidia GT240 (with graphics drivers installed)