Remote checkout - can't log in so can't checkout

Hi i need a bit of help as i spent all day yesterday trying to set up checkout on ecart. All the pages are in place but i was a bit confused with the store summary and details behaviour setup particularly with regards to ids. The data was going into the database but it the id numbers didn't look right, i figured one of the numbers from the orders table should match one of the numbers from the order details table but they were all different.
Anyway, after spending a few hours researching forum and pdfs i found the ecommerce solution recipe for remote checkout. Its the last recipe of the 6. I decided it would be a good idea to restrict access to 'users only' in the checkout process as described in this recipe so i followed the first few steps, i've created a restrict access server behaviour, a recordset and a session variable (MM_UserGroup) (i'm using paypal and php by the way). i've also added the session variable in the server behaviour store summary. i've tried checking out and then logging in with my name and password but nothing happens. Any ideas. I think its best i get the login working before i read any more of the recipe. pls help.