title: Route-Me framework: RMPath becomes invisible if moving map programly
body: <p>I'm using SampleMap example to draw path between 2 points and than move maps from start to end. When map moves, part of path that was out of visible area , becomes invisible until user drag map with finger. Anyone have similar problem? any suggestions to fix that?
  Here is code I'm using to draw path and move map:</p>
  
  <pre><code>//Set map view center coordinate
  CLLocationCoordinate2D center;
  center.latitude = 47.582;
  center.longitude = -122.333;
  slideLocation = center;
  [mapView.contents moveToLatLong:center];
  [mapView.contents setZoom:17.0f];
  
  // Add 2 markers(start/end)  and RMPath with 2 points
  RMMarker *newMarker;
  UIImage *startImage = [UIImage imageNamed:@"marker-blue.png"];
  UIImage *finishImage = [UIImage imageNamed:@"marker-red.png"];
  UIColor* routeColor = [[UIColor alloc] initWithRed:(27.0 /255) green:(88.0 /255) blue:(156.0 /255) alpha:0.75];
  RMPath* routePath = [[RMPath alloc] initWithContents:mapView.contents];
  [routePath setLineColor:routeColor];
  [routePath setFillColor:routeColor];
  [routePath setLineWidth:10.0f];
  [routePath setDrawingMode:kCGPathStroke];
  CLLocationCoordinate2D newLocation;
  newLocation.latitude = 47.580;
  newLocation.longitude = -122.333;   
  [routePath addLineToLatLong:newLocation];
  newLocation.latitude = 47.599;
  newLocation.longitude = -122.333;   
  [routePath addLineToLatLong:newLocation];
  [[mapView.contents overlay] addSublayer:routePath];
  
  newLocation.latitude = 47.580;
  newLocation.longitude = -122.333;   
  newMarker = [[RMMarker alloc] initWithUIImage:startImage anchorPoint:CGPointMake(0.5, 1.0)];
  [mapView.contents.markerManager addMarker:newMarker AtLatLong:newLocation];
  [newMarker release];
  newMarker = nil;
  
  newLocation.latitude = 47.599;
  newLocation.longitude = -122.333;   
  newMarker = [[RMMarker alloc] initWithUIImage:finishImage anchorPoint:CGPointMake(0.5, 1.0)];
  [mapView.contents.markerManager addMarker:newMarker AtLatLong:newLocation];
  [newMarker release];
  newMarker = nil;
  </code></pre>