@Thijs, can you clarify? Why do you put a pair of headphones into line-in? Are you saying you put a headset's mic into the mic in jack?
Also, according to your BIOS, this is what you have, which does not include a line in. Can you verify it's correct?
SPDIF out, rear (0x1f) Mic in, left (0x0a) Headphone out, left (0x0b) Internal speakers (0x0d) Internal mic (0x11)
Mic in, on docking station (0x0e) Line out, on docking station (0x0f)
@Thijs, can you clarify? Why do you put a pair of headphones into line-in? Are you saying you put a headset's mic into the mic in jack?
Also, according to your BIOS, this is what you have, which does not include a line in. Can you verify it's correct?
SPDIF out, rear (0x1f)
Mic in, left (0x0a)
Headphone out, left (0x0b)
Internal speakers (0x0d)
Internal mic (0x11)
Mic in, on docking station (0x0e)
Line out, on docking station (0x0f)