Remember Me Checkbox and a Custom Membership Provider

Hi,

I'm having a problem with the login control using the layout template and a custom membership provider. Basically I can enter the username and password click login and everything is authenticated without any problems and seems to work fine. The problem has arisen since I've added a "Remember Me" check box, I cant seem to get this working.

I've updated my webconfig to stored the details in a cookie - which it does, and I've also added a machine key to the config file: 
<forms name="RememberMeCookie"
timeout="43200"
slidingExpiration="true"
protection="All"
loginUrl="Default.aspx"
defaultUrl="~/ViewCars.aspx"
cookieless="UseDeviceProfile">
</forms>
When I debug the website I can see that this cookie has been created and I can decrypt it t ...