For now, we require a projection on loc internally.

src/ol/Map.js

@@ -329,7 +329,8 @@ ol.Map.prototype.setZoom = function(zoom, opt_anchor) {
             newRes = this.getResolutionForZoom(newZoom);
         newCenter = new ol.Loc(
             anchorLoc.getX() + (size.width/2 - opt_anchor.x) * newRes,
-            anchorLoc.getY() - (size.height/2 - opt_anchor.y) * newRes
+            anchorLoc.getY() - (size.height/2 - opt_anchor.y) * newRes,
+            undefined, this.getProjection()
         );
     } else {
         newCenter = this.center_;

src/ol/renderer/MapRenderer.js

@@ -91,7 +91,8 @@ ol.renderer.MapRenderer.prototype.getLocForPixel = function(pixel) {
         size = goog.style.getSize(this.container_);
     return new ol.Loc(
         center.getX() - (size.width/2 - pixel.x)*resolution,
-        center.getY() + (size.height/2 - pixel.y)*resolution
+        center.getY() + (size.height/2 - pixel.y)*resolution,
+        undefined, this.renderedCenter_.getProjection()
     );
 };