CLLocation Heading Delay iOS4

Question

After

[locationManager startUpdatingHeading];
locationManager.headingFilter = kCLHeadingFilterNone;

• (void) locationManager:(CLLocationManager*)manager didUpdateHeading:(CLHeading*)newHeading { heading = newHeading.trueHeading; heading += -90.0 * roll; NSLog(@"heading"); }

I get the heading once and then there is normally a 20 second delay before I get the next update. After the second update, I get an update every second or more. Has anyone else had issues with this?