The issue is best illustrated using the HoverMenuExtender sample in the Ajax Control Toolkit (you know, this one: http://www.asp.net/AJAX/AjaxControlToolkit/Samples/HoverMenu/HoverMenu.aspx)

Just change the HoverMenuExtender in the GridView ItemTemplate to this:

		   <ajaxToolkit:HoverMenuExtender ID="hme2" runat="Server"
                                    HoverCssClass="popupHover"
                                    PopupControlID="PopupMenu"
                                    PopupPosition="Right"
                                    TargetControlID="Panel9"
                                    PopDelay="25">
                                    <Animations>
                                        <OnShow>
                                            <Sequence>
                                                <HideAction Visible="true" />
                                                <FadeIn Duration=".5" Fps="20" />
                                            </Sequence>
                                        </OnShow>
                                        <OnHide>
                                            <Sequence>
                                                <FadeOut Duration=".25" Fps="20" />
                                                <HideAction Visible="false" />
                                            </Sequence>
                                        </OnHide>
                                    </Animations>
                                    </ajaxToolkit:HoverMenuExtender>

 All I have done is add an 'Animations' section to the existing HoverMenuExtender in the Sample. I have changed nothing else.

Now, if I run it at first everything seems fine. The problems only start after I have triggered a HoverMenu for a row at least once.
After this, clicking on the 'Delete' link in the HoverMenu becomes impossible. Before I get a chance to click, the menu has started fading out to be replaced by the menu for the row below.
It is as if the HoverMenu has become transparent to mouse movements in some way, so the 'mouseover' on the row underneath is triggered 'through' the HoverMenu that is currently showing.

Furthermore, it is possible to trigger the HoverMenu by moving the mouse to the right of the Gridview, i.e. in the space where the HoverMenus would appear.

This is probably best illustrated by trying it out. I have tried all sorts of fixes but I have run out of ideas.

Has anyone else come across this, or can anyone help me out with some pointers on how to explore this further?

 Any thoughts much appreciated...

Thanks

Fixed. It. The short answer is... in the <OnHide> section use:

<HideAction />

instead of

<HideAction = "false" />

I used IE Developer Toolbar to examine what was happening to the styles of the controls involved and found that 'Display: none' was not being set on the popup, as it should be when using <HideAction = "false" />.
I've no idea why this is, although I'm sure stepping through the Animation Toolkit code might bear fruit when I have the time. It is a strange one because <HideAction Visible="true" /> is definitely needed in the <OnShow> section. So surely <HideAction Visible="false" /> would be the opposite of this? Certainly the documentation states this.

But "false" is the default, so just doing <HideAction /> applies this default, which ends up with the desired result.