I recommend moving to openlayers 3 (http://openlayers.org http://openlayers.org) - it's not backward compatible with OL2, but the improvement in user interactio

I recommend moving to openlayers 3 (http://openlayers.org http://openlayers.org) - it's not backward compatible with OL2, but the improvement in user interaction and tile display is worth it, especially on mobile targets. (not affiliated, but use it heavily for my own projects)