void CLClientInvalidate(__CLClient*)",could not send unregistration request to daemon

or…

CLClientRegister: could not send registration request to daemon

If so, you’ve probably already seen this Apple support link:  http://discussions.apple.com/message.jspa?messageID=8408930

Well, I’m just going to validate a few things here for you.  (Before continuing this… check your code after briefly reading this blog.

1. You will have to restore your iPhone.  (This is the solution that worked for me).  Please post a comment if you find a better solution.
2. If you are coding using CLLocationManager you will more than likely notice that you only get 1 set of GPS values before the message starts appearing.  Also, the CLLocationManager startUpdatingLocation method will only call your delegate once.  (That is what was happening on my iPhone).
3. If you dig through your iPhones “crash logs” via the Organizer application, you’ll more than likely witness that many applications are crashing.

I tried a multitude of workarounds and the only thing that sadly worked was a “restore” which took over 1 hour to complete.  I will say this, my iPhone runs a lot faster now!