Windows software supports both sound outputs, but does not auto-detect the change. The Intel software application also does not allow auto-switching between rear stereo speakers and front headphones.
Aslo noted that Intel Audio application software does not have options for USB headphones (only mini-stereo jacks, the most unreliable connector in my 30 years of computer experience). Uninstalled Intel Audio and all is working well. All Windows updates applied (as of 5-23-10), but Microsoft LiveChat LX-3000 headphones would not work. Windows Media Player would not respond to play a music CD. Then a variety of other hangs would also occur. After installing AUD_ALLOS_6224.3_PV_IDTGUI_V182.exe, system shutdown would hang on playing shutdown sound.
Similar problems: DG45ID, replaced DP35DP (not supported for win 7), E8400, 4 GB RAM, all hardware previously working on DP35DP with Win XP.
