RadButton peforms a duplicate request (the second request aborts the first one) when the following conditions are met:

-The page is opened from Visual Studio 2008

- A RadButton exists on the page and the form is submitted when a text box is focused and enter key is hit.

-Default button is not set to the form.

-RadButton's UseSubmitBehavior is set to true

-.NET Framework 3.5 is used.

-The browser is Internet Explorer.

The workaround is to either set Default button for the form or set the UseSubmitBehavior property of the RadButton to false.

When RadButton is set as default button the client side cancel event is not working when pressing Enter key.

When a RadButton is clicked and the following conditions are met:
    -Page validation is not passed
    -Button's postback is cancelled in OnClientClicking event by setting args.set_cancel(true)
the postback of other RadButtons will not be performed.

Currently when the RadButton is clicked and a modal RadWindow that contains another button is opened and then the second button is clicked with enter key, so that it closes the RadWindow, the first RadButton is clicked again. The workaround is to set the Modal property of the RadWindow to false.

When a SingleClick RadButton is clicked and its AutoPostBack property is set to false its disabled state as well as the optional text from the SingleClickText property are persisted. For the time being the SingleClick functionality can be set on the client. For example:
ASPX:
		<script type="text/javascript">
			function DoSubscriptionValidation(button, args) {
				var isPostBack = window.confirm("Perform postback?");
				button.set_autoPostBack(isPostBack);
				if (isPostBack) {
					button.set_singleClick(true);
					button.set_singleClickText("Please Wait");
					button.click();
				}
			}
		</script>
		<telerik:RadButton ID="RadButton1" runat="server" Text="Click"
			OnClick="OnClick1" OnClientClicking="DoSubscriptionValidation" />
C#:
	protected void OnClick1(object sender, EventArgs e)
	{
		System.Threading.Thread.Sleep(2000);
	}

When the RadButton is hovered with the mouse pointer being over the button's text, the hover state is lost. This behavior is observed with Silk and Glow skins under IE 9 or less.

The workaround is to set the ButtonType to "SkinnedButton" or "LinkButton".

When the RadButton is used as a toggle button and some of its toggle state buttons are set with PrimaryIconCssClass property the icons might not be displayed if the following conditions are met at the same time:

-AutoPostBack property of the RadButton is set to false

-One of the togglestate buttons is selected and its PrimaryIconCssClass property is not set.

The issue does not affect the functionality of the button, just the displaying of the icons in the togglestate buttons.

When the PrimaryIconUrl and PrimaryHoveredIconUrl properties of the RadButton are set and a dialog is opened when OnClientClicked event is triggered, the button's icon from the hovered image persists. This behavior is observed only in FireFox.

Currently when the RadButton is focused and the Enter key is pressed, the server-side event OnClick is not triggered. When the Enter key is pressed again, the server-side event is executed.

The issue is reproduced when a dialog is opened in OnClientClicking event.

The workaround is to use

-Either the OnClientClicked event
-OR trigger the server click of the RadButton in the OnClientClicking event:
		<script type="text/javascript">
			function OnClientClicking1(sender, args) {

				alert("Client-click triggered");
				sender.click();
			}
		</script>

When a RadButton with a PostBackUrl property set is located inside an UpdatePanel,  it does not redirect to the PostBackUrl on click and a JavaScript error message is thrown.

The workaround is to use:

- Either a RadButton (ButtonType="LinkButton") and set its NavigateUrl to the desired page that is to be redirected
   
-OR a RadButton (ButtonType="StandardButton") and use its OnClientClicking event handler to cancel the postback and redirect to the desired page through window.location.href. For example:

    <script type="text/javascript">
        function OnClientClicking(sender, args) {

            window.location.href = "http://www.bing.com";
            args.set_cancel(true);

        }
    </script>

When the RadButton, validation controls and controls which are to be validated are set with the same ValidationGroup, the validation is performed despite setting RadButton's CausesValidation property to false.

Currently when the RadButton is used as an Image button:

- There is a flickering on mouse over and mouse out.

- During the postback the image of the current or other image buttons disappears on mouse over/mouse out.

The unexpected behavior is observed under Chrome and page is hosted on Cassini. It is caused due to the image requests that Chrome does for each state of the RadButton - normal and hovered.

When RadButton (ButtonType="StandardButton") is set with a particular width, the text of the button is decentralized. Fix the center of this text. For the time being can be used either the new SkinnedButton or the following workaround:

    <style type="text/css">
        .rbDecorated
        {
            padding-left: 6px !important;
            padding-right: 10px !important;
        }
    </style>

Currently the click event is not triggered when RadButton is focused and enter key is pressed. This behavior is observed in FireFox and WebKit browsers only.

Currently it is not possible to focus RadButton through tabbing navigation unless the TabIndex property is set. For the time being TabIndex of 0 can be set, so that the tab order on the page layout is not distracted. For example:

    <script type="text/javascript">
        function pageLoad() {
            //Getting the button's wrapper
            button1 = $find("<%=RadButton1.ClientID %>");
            buttonWrapper = $telerik.$(button1.get_element());

            //Set tabindex attribute to the span element
            buttonWrapper.attr("tabindex", "0");      
        }                 
    </script>

Note that TabIndex=0 is set to the span wrapper element of the RadButton's input with JavaScript as setting RadButton's TabIndex property to 0 will not take effect.

When the focus of the RadButton is set on the server-side, the active element becomes the inner input and not the span wrapper of the button. 
For the time being the client-side focus can be set. For example:

       	<telerik:RadButton ID="serverFocusBtn" runat="server" RenderMode="Classic" Text="Postback" TabIndex="0" OnClientLoad="btn_load" />
        <script type="text/javascript">
            function btn_load(btn) {
                btn.focus();
            }                 
        </script>

When a RadButton with configured ValidationGroup is used on a master page its server-side event 'Click' is not raised in:
-Internet Explorer and Chrome, but FireFox and Opera.
-In all browsers when the master page contains a RadAjaxManager.

When there is a RadButton with configured ValidationGroup, the client-side ASP.NET validation on the page will not be executed, if there are validation controls, which use the same ValidationGroup. The unexpected behaviour is observed in FireFox and Opera.