diff --git a/lib/yui/blocks/blocks.js b/lib/yui/blocks/blocks.js
index 21cc5f1a7dc..cec719f859b 100644
--- a/lib/yui/blocks/blocks.js
+++ b/lib/yui/blocks/blocks.js
@@ -8,7 +8,6 @@ YUI.add('moodle-core-blocks', function(Y) {
         EDITINGMOVE : 'editing_move',
         HEADER : 'header',
         LIGHTBOX : 'lightbox',
-        PAGECONTENT : 'page-content',
         REGIONCONTENT : 'region-content',
         SKIPBLOCK : 'skip-block',
         SKIPBLOCKTO : 'skip-block-to'
@@ -28,7 +27,8 @@ YUI.add('moodle-core-blocks', function(Y) {
             this.parentnodeclass = CSS.REGIONCONTENT;
 
             // Initialise blocks dragging
-            var blockregionlist = Y.Node.all('#'+CSS.PAGECONTENT+' div.'+CSS.BLOCKREGION);
+            // Find all block regions on the page
+            var blockregionlist = Y.Node.all('div.'+CSS.BLOCKREGION);
 
             if (blockregionlist.size() === 0) {
                 return false;
@@ -84,9 +84,6 @@ YUI.add('moodle-core-blocks', function(Y) {
                         }).plug(Y.Plugin.DDProxy, {
                             // Don't move the node at the end of the drag
                             moveOnEnd: false
-                        }).plug(Y.Plugin.DDConstrained, {
-                            // Keep it inside the .course-content
-                            constrain: '#'+CSS.PAGECONTENT
                         }).plug(Y.Plugin.DDWinScroll);
                     }
                 }, this);
@@ -139,6 +136,10 @@ YUI.add('moodle-core-blocks', function(Y) {
                 return false;
             }
 
+            // TODO: Hiding-displaying block region only works for base theme blocks
+            // (region-pre, region-post) at the moment. It should be improved
+            // to work with custom block regions as well.
+
             // TODO: Fix this for the case when user drag block towards empty section,
             // then the section appears, then user chnages his mind and moving back to
             // original section. The opposite section remains opened and empty.
@@ -151,9 +152,9 @@ YUI.add('moodle-core-blocks', function(Y) {
             }
 
             // Moving from empty region-content towards the opposite one,
-            // hide empty one
+            // hide empty one (only for region-pre, region-post areas at the moment).
             regionname = this.get_region_id(drop.ancestor('div.'+CSS.BLOCKREGION));
-            if (this.dragsourceregion.all('.'+CSS.BLOCK).size() == 0) {
+            if (this.dragsourceregion.all('.'+CSS.BLOCK).size() == 0 && this.dragsourceregion.get('id').match(/(region-pre|region-post)/i)) {
                 if (!documentbody.hasClass('side-'+regionname+'-only')) {
                     documentbody.addClass('side-'+regionname+'-only');
                 }