Code where the crash occurred

gistfile1.txt

- (void)recordLocation:(CLLocation *)location
{
	if (previousRecordedLocation)
	{
		NSTimeInterval interval = [location.timestamp timeIntervalSinceDate:previousRecordedLocation.timestamp];
		NSTimeInterval distance = [location distanceFromLocation:previousRecordedLocation];
		
		CLLocationDistance currentSpeed = distance/interval;
		
		if (previousRecordedSpeed)
		{
			CLLocationDistance speedDelta = (currentSpeed - previousRecordedSpeed)/interval;
			
			if (fabs(speedDelta)>=4.0 || currentSpeed > 120)
			{
				// ignoring implausible speed change
				
				if ([[NSUserDefaults standardUserDefaults] boolForKey:@"FilterSignalDips"])
				{
					return;
				}
			}
		}
		
		previousRecordedSpeed = currentSpeed;
	}
	
	[previousRecordedLocation release];
	previousRecordedLocation = [location retain];
	
	// make new trackpoint
	TrackPoint *newTrackPoint = (id)[NSEntityDescription insertNewObjectForEntityForName:@"TrackPoint" inManagedObjectContext:self.managedObjectContext];
	
	newTrackPoint.latitude = [NSNumber numberWithDouble:location.coordinate.latitude];
	newTrackPoint.longitude = [NSNumber numberWithDouble:location.coordinate.longitude];
	newTrackPoint.horizontalAccuracy = [NSNumber numberWithDouble:location.horizontalAccuracy];
	newTrackPoint.timestamp = location.timestamp;
	
	if (location.verticalAccuracy>0)
	{
		newTrackPoint.altitude = [NSNumber numberWithDouble:location.altitude];
		newTrackPoint.verticalAccuracy = [NSNumber numberWithDouble:location.verticalAccuracy];
	}
		
	if (!trackCurrentlyRecording)
	{
		// make new track
		Track *newTrack = (id)[NSEntityDescription insertNewObjectForEntityForName:@"Track" inManagedObjectContext:self.managedObjectContext];
		newTrack.name = [self.dateTitleFormatter stringFromDate:location.timestamp];
		newTrack.distance = [NSNumber numberWithDouble:0];
		newTrack.beginTimestamp = location.timestamp;
		
		self.trackCurrentlyRecording = newTrack;
	}

	// add to current recording track
	[trackCurrentlyRecording addTrackPointsObject:newTrackPoint];
	
	if (trackCurrentlyRecording.mostRecentTrackPoint)
	{
		CLLocationDistance currentDistance = [trackCurrentlyRecording.distance doubleValue];
		CLLocationDistance addedDistance = [[trackCurrentlyRecording.mostRecentTrackPoint location] distanceFromLocation:location];
		
		currentDistance += addedDistance;
		
		trackCurrentlyRecording.distance = [NSNumber numberWithDouble:currentDistance];
	}
	
	trackCurrentlyRecording.mostRecentTrackPoint = newTrackPoint;
	
	[[NSNotificationCenter defaultCenter] postNotificationName:@"RecordedTrackPoint" object:newTrackPoint userInfo:nil];
	
	NSError *error;
	if (![self.managedObjectContext save:&error])
	{
		NSLog(@"Error saving MOC: %@", [error localizedDescription]);
	}
}