Marker roll over/out events not firing

I have a container that has 2 maps, one being the base map, and the other that contains WMS overlays. I'm trying to add markers to the overlay map and listen on the markerClip for mouse events. MarkerEvent.MARKER_CLICK works fine, but the roll over/out functions are not firing. Here's the code I'm using to add the clip:

map.mouseEnabled = false;
map.grid.mouseEnabled = false;
map.grid.mouseChildren = false;
map.markerClip.mouseEnabled = true;
map.markerClip.mouseChildren = true;

map.removeChild(map.markerClip);
map.markerClip = new PolygonClip(map);
map.addChild(map.markerClip);

map.markerClip.addEventListener(MarkerEvent.MARKER_ROLL_OVER, markerOverHandler);
map.markerClip.addEventListener(MarkerEvent.MARKER_ROLL_OUT, markerOutHandler);
map.markerClip.addEventListener(MarkerEvent.MARKER_CLICK, markerClickHandler);


I'm using the trunk/as3 version of MM.

Any suggestions?