Index: branches/5.0.x/core/admin_templates/js/jquery/thickbox/thickbox.js
===================================================================
diff -u -N -r12117 -r13373
--- branches/5.0.x/core/admin_templates/js/jquery/thickbox/thickbox.js	(.../thickbox.js)	(revision 12117)
+++ branches/5.0.x/core/admin_templates/js/jquery/thickbox/thickbox.js	(.../thickbox.js)	(revision 13373)
@@ -64,6 +64,15 @@
 TB.show = function (params) {
 	TB.lastParams = params;
 //	caption, url, imageGroup, onDataReceived, onAfterShow, postParams
+
+	if (TB.imgLoader === undefined) {
+		// loader image is set from $(document).ready(...) and when some slow javascript
+		// makes page busy and user clicks on something, that opens window, then there will
+		// be an error
+
+		return ;
+	}
+
 	try {
 		if (TB.useStack) {
 			// increment window counter
Index: branches/5.0.x/core/admin_templates/js/grid.js
===================================================================
diff -u -N -r12117 -r13373
--- branches/5.0.x/core/admin_templates/js/grid.js	(.../grid.js)	(revision 12117)
+++ branches/5.0.x/core/admin_templates/js/grid.js	(.../grid.js)	(revision 13373)
@@ -481,34 +481,31 @@
 	this.CheckDependencies('Grid.SetDependantToolbarButtons');
 }
 
-Grid.prototype.CheckDependencies = function($called_from)
-{
-//	alert('prefix: ' + this.prefix + '; ' + $called_from + ' -> Grid.CheckDependencies');
+Grid.prototype.CheckDependencies = function($called_from, $run_now) {
+	if (!$run_now || $run_now === undefined) {
+		// schedule run via document.ready, so we manage to disable
+		// toolbar buttons after ToolBar class mass-enables them
+		var $me = this;
+
+		$(document).ready(
+			function () {
+				$me.CheckDependencies($called_from, true);
+			}
+		);
+
+		return ;
+	}
+
 	var enabling = (this.CountSelected() > 0);
+
 	for (var i = 0; i < this.DependantButtons.length; i++) {
-		if (this.DependantButtons[i][0].match("portal:(.*)")) {
-			button_name = RegExp.$1;
-			if (toolbar) {
-				if (enabling == this.DependantButtons[i][1]) {
-					toolbar.enableButton(button_name, true);
-				}
-				else
-				{
-					toolbar.disableButton(button_name, true);
-				}
-			}
+		if (this.DependantButtons[i][2] == 1) {
+			this.ToolBar.SetEnabled(this.DependantButtons[i][0], enabling == this.DependantButtons[i][1]);
 		}
 		else {
-			if (this.DependantButtons[i][2] == 1) {
-				this.ToolBar.SetEnabled(this.DependantButtons[i][0], enabling == this.DependantButtons[i][1]);
-			}
-			else {
-				this.ToolBar.SetVisible(this.DependantButtons[i][0], enabling == this.DependantButtons[i][1]);
-			}
+			this.ToolBar.SetVisible(this.DependantButtons[i][0], enabling == this.DependantButtons[i][1]);
 		}
 	}
-	//if (enabling) this.ClearAlternativeGridsSelection('Grid.CheckDependencies');
-
 }
 
 Grid.prototype.ClearAlternativeGridsSelection = function (called_from)
Index: branches/5.0.x/core/admin_templates/js/toolbar.js
===================================================================
diff -u -N -r13246 -r13373
--- branches/5.0.x/core/admin_templates/js/toolbar.js	(.../toolbar.js)	(revision 13246)
+++ branches/5.0.x/core/admin_templates/js/toolbar.js	(.../toolbar.js)	(revision 13373)
@@ -94,6 +94,9 @@
 	this.SetOnRightClick()
 	if (this.Hidden) this.Hide();
 
+	// all buttons are disabled until page is fully loaded!
+	this.Disable();
+
 	if (!img.complete) {
 		var real_path = img_path.replace('#MODULE#', this.Module) + 'toolbar/';
 		var old_path = img_path.replace('#MODULE#', 'kernel') + 'toolbar/'+this.ToolBar.IconPrefix + this.Title+'.gif';
@@ -343,6 +346,16 @@
 			btn.Init();
 		}
 	}
+
+	var $me = this;
+
+	$(document).ready(
+		function () {
+			for (var $button_name in $me.Buttons) {
+				$me.Buttons[$button_name].Enable();
+			}
+		}
+	);
 }
 
 ToolBar.prototype.EnableButton = function(button_id) {