Greetings all,
I’ve been noticing that customers on my store that uses 2checkout are having issues checking out. I get repeated instances of customers paying for the same order twice (then emailing and asking me to cancel one) or they are unable to check out at all and leave in frustration. Does anyone else use CS Cart/2CO and have you had similar issues?
Just to confirm that it isn’t CS Cart itself, I have another store with the exact same product line taking payments via Authorize.net, and it functions without issue. Every checkout problem on that store is either the customer making a mistake or me entering stuff wrong in my database 
Thanks,
I've noticed that the customer doesn't get returned to a proper confirmation page after they complete the transaction on 2CO's site. It just takes them to a log in page on my site which is really confusing. Having the same issues and wondering if you found a fix?
Here's the fix that worked for me:
After hours of trying all different combinations today I found a solution (I hope) that works. Within the 2checkout backend in the “Direct Return” section, do NOT use the “Immediately returned to my website option”. This is the one I've always used in the past but now it is the only one that will give you major problems. Instead, use the “Header Redirect (Your URL)” and things work as they should.
CS manual says you should use the “Given links back to my website” but I do NOT recommend that one either. The reason being is the customer is given the option to go back to your site after payment is made or not visit your site. If they do not click the link to take them back to your site the order is approved but is marked as “incompleted” within the CS backend. It will be set to approved (or whatever status you have set up for fraud review) ONLY if they click the link that takes them back to your site.
Hopefully this will help others out as this has been driving me nuts for the past few weeks.