diff --git a/src/wp-admin/js/editor.js b/src/wp-admin/js/editor.js
index 6136e6ba80..e718716355 100644
--- a/src/wp-admin/js/editor.js
+++ b/src/wp-admin/js/editor.js
@@ -13,7 +13,7 @@ window.switchEditors = {
 
 	// mode can be 'html', 'tmce', or 'toggle'; 'html' is used for the 'Text' editor tab.
 	go: function( id, mode ) {
-		var t = this, ed, wrap_id, txtarea_el, editorHeight, toolbarHeight,
+		var t = this, ed, wrap_id, txtarea_el, iframe, editorHeight, toolbarHeight,
 			DOM = tinymce.DOM; //DOMUtils outside the editor iframe
 
 		id = id || 'content';
@@ -32,17 +32,14 @@ window.switchEditors = {
 		}
 
 		function getToolbarHeight() {
-			var height;
+			var node = DOM.select( '.mce-toolbar-grp', ed.getContainer() )[0],
+				height = node && node.clientHeight;
 
-			try {
-				height = DOM.getSize( DOM.select( '.mce-toolbar-grp', ed.getContainer() )[0] );
-			} catch(e){}
-
-			if ( height && height.h && height.h > 10 && height.h < 100 ) {
-				return height.h;
+			if ( height && height > 10 && height < 200 ) {
+				return parseInt( height, 10 );
 			}
 
-			return 0;
+			return 30;
 		}
 
 		if ( 'tmce' === mode || 'tinymce' === mode ) {
@@ -63,8 +60,9 @@ window.switchEditors = {
 			if ( ed ) {
 				ed.show();
 
-				if ( editorHeight && ( toolbarHeight = getToolbarHeight() ) ) {
-					editorHeight = editorHeight - toolbarHeight + 11;
+				if ( editorHeight ) {
+					toolbarHeight = getToolbarHeight();
+					editorHeight = editorHeight - toolbarHeight + 14;
 
 					// height cannot be under 50 or over 5000
 					if ( editorHeight > 50 && editorHeight < 5000 ) {
@@ -73,9 +71,6 @@ window.switchEditors = {
 				}
 			} else {
 				tinymce.init( tinyMCEPreInit.mceInit[id] );
-
-		//		ed = tinymce.createEditor( id, tinyMCEPreInit.mceInit[id] );
-		//		ed.render();
 			}
 
 			DOM.removeClass( wrap_id, 'html-active' );
@@ -89,11 +84,12 @@ window.switchEditors = {
 			}
 
 			if ( ed ) {
-				editorHeight = DOM.get( id + '_ifr' );
-				editorHeight = editorHeight ? parseInt( editorHeight.style.height, 10 ) : 0;
+				iframe = DOM.get( id + '_ifr' );
+				editorHeight = iframe ? parseInt( iframe.style.height, 10 ) : 0;
 
-				if ( editorHeight && ( toolbarHeight = getToolbarHeight() ) ) {
-					editorHeight = editorHeight + toolbarHeight - 11;
+				if ( editorHeight ) {
+					toolbarHeight = getToolbarHeight();
+					editorHeight = editorHeight + toolbarHeight - 14;
 
 					// height cannot be under 50 or over 5000
 					if ( editorHeight > 50 && editorHeight < 5000 ) {
diff --git a/src/wp-admin/js/post.js b/src/wp-admin/js/post.js
index 0811471ddf..0e3e824957 100644
--- a/src/wp-admin/js/post.js
+++ b/src/wp-admin/js/post.js
@@ -1014,13 +1014,18 @@ jQuery(document).ready( function($) {
 			if ( mce ) {
 				editor.focus();
 				toolbarHeight = $( '#wp-content-editor-container .mce-toolbar-grp' ).height();
+
+				if ( toolbarHeight < 10 || toolbarHeight > 200 ) {
+					toolbarHeight = 30;
+				}
+
 				height = parseInt( $('#content_ifr').css('height'), 10 ) + toolbarHeight - 28;
 			} else {
 				$textarea.focus();
 				height = parseInt( $textarea.css('height'), 10 );
 			}
 
-			$document.off( 'mousemove.wp-editor-resize mouseup.wp-editor-resize' );
+			$document.off( '.wp-editor-resize' );
 
 			// sanity check
 			if ( height && height > 50 && height < 5000 ) {
@@ -1045,10 +1050,10 @@ jQuery(document).ready( function($) {
 			}
 
 			$document.on( 'mousemove.wp-editor-resize', dragging )
-				.on( 'mouseup.wp-editor-resize', endDrag );
+				.on( 'mouseup.wp-editor-resize mouseleave.wp-editor-resize', endDrag );
 
 			event.preventDefault();
-		});
+		}).on( 'mouseup.wp-editor-resize', endDrag );
 	})();
 
 	if ( typeof tinymce !== 'undefined' ) {