Accessing masterpage properties from server.transfer page?

I'm using ASP.NET 2.0 with VS.NET 2005. I'm trying to access properties
from my master pages within a page that inherits from that master page (a
child page). However the values are always null.

In my masterpage I have this:

private bool m_AlreadyTested;
public bool AlreadyTested
{
get { return m_AlreadyTested; }
set { m_AlreadyTested = value; }
}

Then within the Page_Load of the master page I am doing this:

if certainConditions == true then
AlreadyTested = true;
Server.Transfer("/error.aspx");
end if

Then in error.aspx child page (derrived from the master page) I do this from
its Page_Load event:
Response.Write(Master.AlreadyTested.toString());

However the AlreadyTested always displays as FALSE, even though itis hard
coded to True. When I step through in the debugger I can see it is set to
True just prior to the Server.Transfer. But once it gets into the transfered
page everything is nulled out and bools are set to False.

Similarly I have other properties I've set to valid object instances prior
to the .Transfer and afterward those are all Null too.

What is going on here? I thought under ASP.NET 2.0 I could tap into the
master page properties even from exceution of the .Transfer pages?

Thanks!