Label in Vector Layer moving to incorrect position after drag the map

Label/point/line or any other feature in Vector Layer moving to incorrect position after drag the map. I change label(feature) postion in code every 10 seconds. If I drag the map, it will be in incorrect location. It seems vector layer not updated after dragging map unless I zoom the level or zoom in/out, but It costs a lot and lags the application about 1 second everytime. Markers layer works perfectly, just Vector Layer. Any one has the same problem? Help me out please!

What software are you talking about? Are you using Leaflet or Khtml?

It is Openlayers. I am using Openlayers & OSM in .net 4.0 Web Browser control. Actually I also try html with my code in IE & firefox. Same problem. It seems vector layers won’t move with map. Is there any way I could upload a attachment?