Forms Authentication issue. works in debugger, not live.

Hello,
really need some help/suggestions with a Forms Authentication issue
I have a web application in VB.net and using VS 2005, on WinXP

what is happeneing, is that ONLY on my local environment
authentication is not taking place correctly
it does not work at all in IE, it kinda works in firefox, it works
perfectly with running the site via visual studio debugger

It seems to have been an issue only since i've rebuilt my PC (a guess
as this point). the application works fine on our server and other
developers PCs, so the code is working, there is just something about
my local setup/configuration that we can not figure out.

page flow:

going from the homePage (which is open to the public)









from there i click on the SignIn.aspx page, after entering
usernanme/pswd, it looks up in the database, if valid, the forms auth
ticket/cookie is created.

tkt = New FormsAuthenticationTicket(1, Login.ToUpper, DateTime.Now(),
DateTime.Now.AddMinutes(30), True, "FACookie")
cookiestr = FormsAuthentication.Encrypt(tkt)
ck = New HttpCookie(FormsAuthentication.FormsCookieName(), cookiestr)

ck.Path = FormsAuthentication.FormsCookiePath()
Response.Cookies.Add(ck)

' create/populate user session (snipped out to save space)

Response.Redirect(strRedirect, True)
'strRedirect could be one of many destinations after logging in


this is the forms auth setup in web.config


protection="All" path="/" timeout="720"/>






this is where the issue occurs, after clicking the "login" button and
then going thru the authentication process.

IE will immediately send me back to signin page, as the ticket/cookie
don't exist.
watching the IIS logs via logparser, no cookies are generated.

Firefox will sit there and spin, almost as if it is hung on the
redirection. i see in the URL bar it has changed to
the next page. If i hit stop on the browser and then refresh (with the
next url still in the url-bar) the page will
load up fine and my session is created and web session authenticated.
I can view the cookies for the session and both the ASPXFORMS cookie
and Session_Id cookie are present.

when i run the app via Debugger in visual studio, the site works
perfectly fine, using both IE and FF as the debuggers default browser.

I checked out the setting in IIS and under the ASP.NET tab (set to
v2.0.50727, by the way),clicking the edit configuration button,
Authentication is set to Forms

also in the web.config i have added an impersonate tag to see if that
would help any


(real values for admin account exist in file)


I have search all over the net for days and have tried everything i
read about and i'm completely stuck
even when i create a new test web app project, that just has a default
page, signin page, page-after-signin
and using hardcoded username/password checks in the codebehind, it
still acts the same way as the full application.


any suggestions would truly be appreciated. it is impossible to
develop locally currently. I'm at a loss of what to try next or what
to look for.

thank you