Empty Basket bug

[grafis]

Issue: Customer spends time making a Basket which they can see but when they click "View Basket" to checkout they're presented with an empty Basket and all their work is gone.

Two customers reported the issue this week - one had 48 products & 248 items total in their Basket which she was able to view using the back button and then copy paste to send in as an (angry) order. 

Is this something I've screwed up, an issue with 5.2.1 ?

 

How it happens: appears there is a cookie set to last 1hr that I have no control over and the visitor has no knowledge of? Odd as in the past we've had this issue (with CC5, never CC4) and items would stay in the Basket for days and I swear i could log into another browser and see my Basket - currently I loose the basket immediately at logout, loose it between browsers and ultimately as I believe is happening to users when their session cookie expires.

1. Admin > Settings > features > "Time before expiring pending orders" set to 1209600 seconds (two weeks - set that high after the last rash of Empty Basket)
    
2. Visit Website - all visitors go to: http://www.domain.com  (always HTTP except for login and basket/checkout (https), always WWW)
    
3. Cubecart sets 5 cookies:
   1. PHPSESSID for www.domain.com  set to expire in 1hr
   2. __atuvc for .domain.com set to expire in 2 days 

   3. __utma for .domain.com set to expire in 2 days

   4. __utmb for .domain.com set to expire in 30 minutes

   5. __utmc for .domain.com set to expire "session" (when browser closes)

   6. __utmz for .domain.com set to expire in 23hrs
       

4. ​Customer Logs in

   1. PHPSESSID cookie is updated to expire one hour from their login time

       

5. Customers shops, adds items to their Basket

    

6. Customer clicks "View Basket" and... punches screen. 

 

Notes: 

1. Custom Skin 
2. Mod - Privacy Manager by GWorks mod