The page editor is not yet available

I have recently experiment a bug with the webedit mode in sitecore 6.4.1. When I try to add some components on some pages I have this message: "The page editor is not yet available".

In fact, it append if a layout or a sublayout contains an ASP.NET LinkButton with a PostBackUrl attribute

As a workaround, you can wrap your line with PostBackUrl attribute in the “if” clause like this:

if ((!Sitecore.Context.PageMode.IsPageEditor) && (!Sitecore.Context.PageMode.IsPreview))
{
       lbLink.PostBackUrl = Utils.GetUrlFromGeneralLink(tmpItem, "Link");
}

Thank you to the sitecore support. I will maybe see some of you at the London dreamcore :)