It's happening to my phone with the lastest kitchen (12/17/07 I believe is the date), but I just read that the problem's been replicated with the newest version of advanced configuration installed. I don't know if that's the culprit.

I have done some testing, and it is my theory that is has to do with keeping the data connection open. try using Advanced config and making sure that the option to keep the data connection alive is NOT selected. This seemed to fix the problem after a soft reset.

Also another note, it seems to happen W/O Advanced Config, the registry entry is as follows:
HKLM\Comm\ConnMgr\Providers\{7c4b7a38-....}\Connections\Data Network Connect\
AlwaysOn <--- Set this to 0 if a 1 is present.

Does this fix the problem for anyone?

In my experience with this problem, it was always caused by a 3rd party application (mainly the ones that use the internet for one thing or another) not functioning correctly. I would eliminate one app at a time to identify the culprit. A lot of 3rd party "push" mail apps cause this problem. IE: mail2web, emoze, etc.

This has been my problem when ever I have an active data connection.
If I end the data connection the phone works fine?
I have been testing it out and the only thing I have found is the data connection being broken (ended) will get the phone to work with out going to speaker phone!
I am using WM6 from,
http://forum.ppcgeeks.com/showthread.php?t=11074

I have found a termp fix,
Install Bluemusic 2.0 then in settings turn off auto speaker phone.
Now if we can get a guru to figure what bluemusic is doing to turn auto speaker phone on/off (maybe reg hack) we could get this fixed without adding yet another app!

I read in another thread that Advanced Configuration 1.1 seemed to be the culprit; I exchanged 1.0 for the 1.1 that I had had when I was having the speakerphone problem, and now I don't seem to being having a problem.

I've been having the missed call symptom and the unable to answer call problems as well. I'm reflashing with Advanced Config removed and we'll see what happens.

Where did you find Advanced Configuration version 1.0 ? I can't seem to find it!
Thank you,
David

It's for sure due to 1.1 I would assume you could pull 1.0 from the last kitchen and put it in USER_OEM's.

Ok I got ver 1.0 from the old kitchen, I just copied the exe of ver 1.0 to my windows folder and now ver 1.1 is gone. All I need to know now is what reg entry to change back so my phone dont go to speaker every time I am in a data call!
Any pro's out there know what I need to change back?
Thank you,
David