Session disappears when I leave site

My program allows users to create an account to login, etc. like most
other programs. I am using the login routine supplied by rails.

In my program I have an option to ‘add funds’ to the account. When the
user selects this option I ask them how much they want to pay, etc., I
then take this info and the user is taken to an payment
page (I pass the data that needs in order to processs the

If everything goes well, the user gets charged and is
instructed to call one of my controllers.

It calls the controller successfully – there’s only one problem. The
session and cookies that were created have suddenly disappeared so I
can’t retrieve them and the login screen keeps appearing right after a
successful (or unsuccessful) transaction.

What did rails do with the session? Did leaving to another site and then
returning ‘destroy’ the sessions?

Any advice or recommendations?

(Please note that I am aware of the rails payment library.
If you have any information regarding my ‘bug’ above though I would
sincerely appreciate it rather than just recommending I use the lib. thanks)