I have been using an HP 2.6 GHz desktop tower with OEM WinXP MCE 2005 for my Media Center system.  This has been working well with the HP Extender over 11g wireless (yes, really).

Recently it started acting up (e.g. throwing some error about NET.EXE on the main MCE PC screen, also apparent random crashes when accessing "Movies") so I switched over to a Shuttle XPC SB61G2 with P4 2.8 GHZ HT.  (None of which is really very interesting, but for background anyway).  I reinstalled XP 2005 Media Center from scratch, which has been pretty difficult, as I made the mistake of installing XP SP3, thinking this would make things easier - it didn't (but I did locate a blog talking about the registry key to patch to make it OK).

By the way, that link is:

Aaron Stebner's WebLog : Possible issue running Xbox 360 PC setup on a Window XP SP3 system with Media Center 2005 installed

So, everything works pretty well now on the Shuttle, but channel change from the extender is not working.

I have a Linksys extender, HP extender (which is what I have been using at home) and Xbox 360.

None of them will channel change from keyboard input, channel up/down, or the program guide.   The onscreen popup banner indicating which channel MCE "thinks" it's on does change, but no IR commands are being sent.  However, if I press "record", either from Live TV or the Guide, the channel change will be sent correctly to whatever channel MCE thinks it's on from Live TV, or to the selected channel in the Guide.

There's one final variable here - I am using the HAVA network tuner/video input device, which replaces the IRBlaster.DLL with its own file and reroutes the channel change requests to its own IR blaster circuitry to control the set top box.

But wait, there's more - the HP system that HAD BEEN WORKING with the HP extender, now doesn't work properly either.  Same behavior as the newly set up Shuttle.  The only thing I did was to run the extender setup program to configure this for the other devices - Linksys and Xbox 360.

Anyone have any clue what's going on?

Thanks a ton,

DL

The gotcha here is that HAVA (my "tuner") catches signals (events?) sent through MSAS to change channels from its  built in IR blaster.  And the answer to this dilemma is:

Create a new registry key:

HKLM\Software\Microsoft\Windows\CurrentVersion\Media Center\Service

AlwaysUseFPD = 1 (DWORD)

If using XP MCE, stop and restart Media Center. If using Vista, restart your PC.