We had the same issue, and disabling Facebook Connect solved it. We had also tried the cookie_domain setting, as well as putting /cart under https. Now if we can just figure out why seemingly random orders stay in Payment Received and don't Complete, we'd be super happy 
Facebook connect
Wed, 06/30/2010 - 21:34
#1
Facebook connect
Cart becomes empty upon checkout - HTTP to HTTPS on different domains By: brad (30 replies) Thu, 04/16/2009 - 18:33
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: wigle (02/23/2012 - 11:48)
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: awebmanager (04/02/2011 - 11:14)
- Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on diff By: tr3online (04/03/2011 - 04:40)
- Re: Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on By: awebmanager (04/03/2011 - 08:59)
- Had this problem... And finally fixed it By: peternemser (08/15/2011 - 00:55)
- Re: Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on By: awebmanager (04/03/2011 - 08:59)
- Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on diff By: tr3online (04/03/2011 - 04:40)
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: ixlr8 (04/01/2011 - 05:17)
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: milkrow (03/31/2011 - 08:07)
- Can't resolve this problem :-( By: awebmanager (03/31/2011 - 03:16)
- Re: Can't resolve this problem :-( By: ixlr8 (03/31/2011 - 03:26)
- Re: Re: Can't resolve this problem :-( By: awebmanager (03/31/2011 - 04:05)
- Re: Re: Re: Can't resolve this problem :-( By: ixlr8 (03/31/2011 - 04:09)
- Re: Re: Re: Re: Can't resolve this problem :-( By: awebmanager (04/01/2011 - 02:18)
- Re: Re: Re: Re: Re: Can't resolve this problem :-( By: ixlr8 (04/01/2011 - 02:21)
- Re: Re: Re: Re: Re: Re: Can't resolve this problem :-( By: awebmanager (04/01/2011 - 04:11)
- Re: Re: Re: Re: Re: Can't resolve this problem :-( By: ixlr8 (04/01/2011 - 02:21)
- Re: Re: Re: Re: Can't resolve this problem :-( By: awebmanager (04/01/2011 - 02:18)
- Re: Re: Re: Can't resolve this problem :-( By: ixlr8 (03/31/2011 - 04:09)
- Re: Re: Can't resolve this problem :-( By: awebmanager (03/31/2011 - 04:05)
- Re: Can't resolve this problem :-( By: ixlr8 (03/31/2011 - 03:26)
- Had the same problem By: ixlr8 (01/06/2011 - 19:03)
- same here By: Stephanie_42 (11/01/2010 - 14:39)
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: jgarbe02 (03/10/2010 - 16:36)
- Facebook connect By: incrn8@drupal.org (06/30/2010 - 21:34)
- Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on diff By: jasonabc (05/17/2010 - 18:38)
- Cart becomes empty upon checkout - HTTP to HTTPS on diff By: brad (05/18/2010 - 12:14)
- Cart is suddenly empty when clicking "your shopping cart" By: milkrow (01/25/2011 - 13:02)
- Cart becomes empty upon checkout - HTTP to HTTPS on diff By: brad (05/18/2010 - 12:14)
- Empty Cart By: kathryn531 (08/20/2009 - 15:18)
- Re: Empty Cart By: deepakg83 (08/20/2009 - 16:45)
- Re: Re: Empty Cart By: kathryn531 (08/21/2009 - 12:49)
- Re: Re: Re: Empty Cart By: torgosPizza (08/30/2009 - 19:30)
- Re: Re: Empty Cart By: kathryn531 (08/21/2009 - 12:49)
- Re: Empty Cart By: deepakg83 (08/20/2009 - 16:45)
- Re: Cart becomes empty upon checkout - HTTP to HTTPS on differen By: torgosPizza (04/16/2009 - 19:27)
- Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on diff By: coworks_dieter (10/06/2010 - 16:20)
- Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on diff By: Troy Dalmasso (08/10/2009 - 14:39)
- Re: Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on By: Troy Dalmasso (08/10/2009 - 15:44)
- Re: Re: Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS By: torgosPizza (08/11/2009 - 00:15)
- Re: Re: Re: Cart becomes empty upon checkout - HTTP to HTTPS on By: Troy Dalmasso (08/10/2009 - 15:44)