Forms authentication is not happening in MAC OS 9.5

[Guest]

hi,
I am facing a strange forms authentication problem in IE 5.0 browser in MAc
OS X 9.5
I could not test it in safari.
this code:

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = User.Identity.IsAuthenticated;
}
protected void Button1_Click(object sender, EventArgs e)
{
FormsAuthentication.SetAuthCookie("Cust1", false, "/");
}
}
when i click the button in IE or Firefox the user is being authenticated
..While inspecting the the generated cookie i
got the path is set as / ,as it should be.
But when i am testing this code in MaC OS 9.5 ie 5 the user is not being
authenticated and the cookie path is being set as /; and is showing as
disabled.
Although Anonymous cookie path is set as / and it is showing as enabled.
here is my web config:

<authentication mode="Forms">
<forms name=".ASPXCOOKIEDEMO" protection="All" timeout="30" path="/">
</forms>
</authentication>
When i use cookiles authentication it works fine in MAc also.
What could be the problem with Authentication cookie?
Thanks
abhijit