iOS 4.1 CLLocationManager delegate stops getting called - RunLoop blocked?

OK, this one has me stumped. I use the CLLocationManager services (iOS 4.1) in my application. The delegate gets called as it should at first. Then (some arbitrary time interval later), the delegate stops getting called. It almost looks like that RunLoop is getting blocked somewhere.

I have even reduced the callback to one NSLog statement, and I see the same behavior. Do we have any gdb experts out there w开发者_开发百科ho could give me some hints how to look at all of the running threads, and determine which one is blocked where ?

As a test, I have also put a button on the GUI which stops are starts both heading and location updates - this seems to unjam things for a while.

Other info: This is on an iPhone 4, app has been run through Instruments (leaks and allocations), everything looks good there. Any hints would be appreciated, I am currently out of ideas...

Mea culpa... I had errant logic which was firing a timer, shutting off the service. One again, caution is called for when making supposed "small" changes. My apologies if anyone wasted effort on this one....