ASP.NET login control mysteriously stops working
<p>I'm using the ASP.NET Login control and have been doing so for a couple of years on a particular site with success. Out of the blue, in the dev environment, this control has stopped working and is now bouncing me back to the login page.</p>

<p>Using source control I've reverted recent changes that might have been the cause but no luck. I've stepped through the code and have checked that the e.Authenticated property is correctly being set to true and that the ReturnUrl is correctly specified on the params.</p>

<p>Any ideas about where to look next to try and figure this out?</p>
