Simultaneous speaker and headphone sound since yesterday [Dell XPS M1710]

Thank you for reporting. Please attach the information requested on https://wiki.ubuntu.com/KernelTeamBugPolicies and https://help.ubuntu.com/community/DebuggingSoundProblems

I also occasionally see this after resuming my laptop (dell d620) - although it doesn't seem to be every time.

amixer:
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 21 [68%] [-15.00dB] [on]
  Front Right: Playback 21 [68%] [-15.00dB] [on]
Simple mixer control 'PCM',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 255
  Mono:
  Front Left: Playback 31 [12%] [-44.80dB]
  Front Right: Playback 31 [12%] [-44.80dB]
Simple mixer control 'IEC958',0
  Capabilities: pswitch pswitch-joined cswitch cswitch-joined
  Playback channels: Mono
  Capture channels: Mono
  Mono: Playback [off] Capture [off]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 15
  Front Left: Capture 14 [93%] [21.00dB] [on]
  Front Right: Capture 14 [93%] [21.00dB] [on]
Simple mixer control 'Capture Mux',0
  Capabilities: volume
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 4
  Front Left: 0 [0%] [0.00dB]
  Front Right: 0 [0%] [0.00dB]
Simple mixer control 'Digital',0
  Capabilities: cvolume
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 120
  Front Left: Capture 60 [50%] [0.00dB]
  Front Right: Capture 60 [50%] [0.00dB]
Simple mixer control 'Input Source',0
  Capabilities: enum
  Items: 'Mic' 'Front Mic' 'Line'
  Item0: 'Front Mic'

lspci -vv:
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
    Subsystem: Dell Unknown device 01c2
    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
    Latency: 0, Cache Line Size: 64 bytes
    Interrupt: pin A routed to IRQ 20
    Region 0: Memory at efffc000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: [50] Power Management version 2
        Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
        Status: D0 PME-Enable- DSel=0 DScale=0 PME-
    Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
        Address: 0000000000000000 Data: 0000
    Capabilities: [70] Express Unknown type IRQ 0
        Device: Supported: MaxPayload 128 bytes, PhantFunc 0, ExtTag-
        Device: Latency L0s <64ns, L1 <1us
        Device: Errors: Correctable- Non-Fatal- Fatal- Unsupported-
        Device: RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+
        Device: MaxPayload 128 bytes, MaxReadReq 128 bytes
        Link: Supported Speed unknown, Width x0, ASPM unknown, Port 0
        Link: Latency L0s <64ns, L1 <1us
        Link: ASPM Disabled CommClk- ExtSynch-
        Link: Speed unknown, Width x0

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this bug to the new "linux" package. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!

The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:

1) If you are comfortable installing packages on your own, the linux-image-2.6.27-* package is currently available for you to install and test.

--or--

2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch http://www.ubuntu.com/testing for Alpha5 to be announced. You should then be able to test via a LiveCD.

Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.

Fixed upstream since long.