EXPERT: CANT LOGOUT! User remains authenticated

Management summary: HELP!

I can login into my site, no problem (even though .MyCookie is created twice, dont know how or why)
BUT:
I cant logout of my site, I've tried everything (except the right thing I guess :p)

NOTE: I use dynamic subdomains, so a logged in user must be authenticated for both peter.mysite.com as www.mysite.com


Here's the control on my masterpage:
MYMASTER.MASTER
<asp:LoginStatus OnLoggedOut="ClearAllData" ID="LoginStatus1" runat="server" LogoutPageUrl="http://www.mysite.com/" LogoutText="<%$Resources: Glossary, LogoutText%>" LoginText="" LogoutAction="Refresh" />

MYMASTER.MASTER.VB
Sub ClearAllData(ByVal sender As Object, ByVal e As EventArgs)
    'i've added a breakpoint and this method is really called
    Request.Cookies.Clear()
   &n ...