Laptop speaker vs earphone

[Lion G.]

Hi all, I have a weird question.

In my previous many laptops, whenever I plug in
the earphone, the laptop speaker would stop
(and I would only hear music through the earphone)

With my newest laptop (Acer Aspire 5050),
the laptop speaker stays on no-matter-what.
I would hear the same music in both
the speaker and the earphone.

I'm using Ariff Abdullah's snd_hda driver on 6.2-RC2.
The driver reports:
pcm0: <ATI SB450 High Definition Audio Controller> mem 0xc0000000-0xc0003fff 
irq 16 at device 20.2 on pci0
pcm0: <HDA Codec: Realtek ALC883>
pcm0: <HDA Driver Revision: 20061210_0037>

Another piece of info:
The microphone hole has both the microphone symbol
and the SPDIF symbol on it. Apparently the laptop
uses the same hole for both plugging in a stereo microphone
and plugging in a SPDIF device.

Also, none of the items in the mixer helps:
they raise or drop both the speaker+earphone volume simultaneously.

I'm out of ideas. Has any one seen something like this?

Thanks all!

_________________________________________________________________
Fixing up the home? Live Search can help 
http://imagine-windowslive.com/search/kits/default.aspx?kit=improve&locale=en-US&source=hmemailtaglinenov06&FORM=WLMTAG