Vista - Cached Passwords disappear!

I have a couple non-domain users that accessed our network daily with no issues. Now they are prompted for a username/password whenever they try and access Exchange, Intranet, network shares, etc..... They put in their username and password and "Remember my password", and it gives them access. You can see their Passwords get cacahed in Manage Network passwords, however as soon as they reboot, Manage Network Passwords is empty and they are prompted for a password again. Any Ideas?

what your saying is ...
if you click remember my password and username people can get in to your stuff ?

answer = thats correct

but if you untick that box and someone gets into your stuff they wont get nothing as the buttom to remember me is not on ...

answer =if unticked they cant get nothing

hope this helps

To clarify the situation... It doesn't matter if they check the remember my password box or not they are prompted for a password. They can access the network when they manually put in their password everytime so access to the network is not an issue. It is the passing of the saved username/password that isnt working.. The OS should cache their password and pass the credentials but it doesn't. When they check the box you can see their username and password get saved in Manage Network Passwords, but it still prompts for a password and doesn't pass the saved data. Then after a reboot the Manage Network passwords is empty. Hopefully this clarify's the issue.