Hi Roger, This seems to only occur when a customer uses the quick buy button.
Not too sure why to be honest, but I'll look into it and get back to you. Meanwhile you could remove the quick buy button until the issue is sorted out.
Hi Roger, I can reproduce this on my PHP version but I'm not too sure what the issue is, so we'll just have to wait until Vince gets back from his break.
Rolling back to an earlier version does fix it though, but that's really not an option.
I've fixed this, so if you'd like to check the pm I've sent you with a download link. The fix is in the js/ectcart.js file. so just upload it and make sure you clear your browser cache or force a page refresh (ctrl + F5)