There is a solution which will be included in the next release. Open DesktopModules/Bring2mind/DMX/Views/AjaxTwoPanel.ascx in a text editor. At line 24 you’ll see this block of code:
function callbackComplete(sender, eventArgs)
{
<%= mnuContext.ClientID %>.showContextMenu(_MouseX, _MouseY);
};
Please change that to:
function callbackComplete(sender, eventArgs)
{
<%= mnuContext.ClientID %>.showContextMenuAtPoint(_MouseX, _MouseY);
};