When user navigates to a sub list via backspace, hitting enter twice removes the nested list.

This is reproducible in IE9+. In IE11 the steps may lead to browser crash.

When the Editor is set with Skin=Window7, fieldsets has a non designed margin top value. The New Area bottom also drop to a new line, where it should be next to the radio buttons. 

Possible solutions is setting a CSS file to the DialogsCssFile property with CSS rules that resolve the issue:

<telerik:RadEditor ID="RadEditor1" runat="server" Skin="Windows7" DialogsCssFile="~/Styles/Styles.css">
</telerik:RadEditor>


Styles.css

html.redImageMapDialog.RadForm_Windows7 #dialogControl fieldset {
	margin-top:0;
}


button#ImageMap_NewArea {
	width:110px !important;
}

Currently the lightweight rendering of RibbonBar used in RadEditor with lightweight rendering leads to visual issues.

When trying to align selected text in a table, not all cells are being aligned correctly under IE and Chrome. In Firefox only one table cell is being applied with the chosen modification and not the selected text.  

Under IE and Chrome, when a table row element is in the selection, the child td elements are not processed by the Align command.

Under FF when the table text is selected, the selected element is only the first TD element. 

The problem under IE and Chrome could be resolved using the following override of the executeOnNode():

<telerik:RadEditor runat="server" ID="RadEditor1">
</telerik:RadEditor>

<script type="text/javascript">
	Telerik.Web.UI.Editor.AlignCommand.prototype.executeOnNode = function (node) {
		var utils = Telerik.Web.UI.Editor.Utils;

		if (utils.isTag(node, "table"))
			return;//prevent alignment of tables since this has no effect in browsers.

		if (utils.isTag(node, "tr")) {
			var nodes = node.childNodes;
			var nodeArr = [];

			for (var i = 0; i < nodes.length; i++) {
				nodeArr.push(nodes[i]);
			}

			while (nodeArr.length) {
				var childNode = nodeArr.shift();
				if (this.isSuitableNode(childNode))
					this.executeOnNode(childNode);
				else
					this.executeInlineNode(childNode);
			}

			return;
		}

		if (utils.isTag(node, "ul") || utils.isTag(node, "ol"))
			return this.executeDomCommand($.makeArray(node.children));

		if (utils.isTag(node, "img")) {
			if (this.nodes.length == 0 && this.canAlignImage()) {
				if (this.options.align == "none")
					this.alignBlock(this.getBlockContainer(node));

				return this.alignImage(node);
			}
			else {
				this.removeImageAlign(node);

				var imageContainer = this.getBlockContainer(node);
				if (imageContainer != node)
					this.executeOnNode(imageContainer);
				else
					return this.executeInlineNode(node);
			}
		}

		this.alignBlock(node);
	};
</script>

MaskedTextBoxSetting set with numbers in the mask does not allow numbers to be entered from the number pad area of the keyboard.

RadImageGallery fullscreen mode overrides viewport meta tag set on page.
If the user sets the following meta tag:

<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1, maximum-scale=1.0, user-scalable=no, height=device-height" />

initially the page is not scalable. When the Gallery enters fullscreen mode, the page is zoomed out.
And when you exit fullscreen, the page stays zoomed out, the gallery proportions are changed and fonts are smaller.

Will work in Q2 2014

Creating a large page with RadEditor control and opening the mentioned dialog will scroll the page to the top. This causes the user to loose visual  contact with the Editor.

The issue is due to the automatic textarea focusing in the clientInit() method of the dialog's logic.

To resolve the issue you should modify the dialog and remove the focusing functionality. To do so follow the next steps:

    1. Follow the Custom Built-in dialogs approach (http://demos.telerik.com/aspnet-ajax/editor/examples/externaldialogspath/defaultcs.aspx) to use an external and later modified Plain Paste Dialog - the MozillaPasteTextDialog.ascx;
    2. Find the clientInit() method trough the client-side logic of the MozillaPasteTextDialog.ascx file;
    3. Remove the this._container.focus() line.

You can also find attached a sample page with the fix placed, so that you can examine it.