Quote Originally Posted by carlwhat View Post
well, in looking at the code, it does "seem" to be an easy way around this. you can just comment out the error check.
Turns out it's not that file but the /modules/quickcheckout.php which disables the error. You can disable the error and continue on a checkout, but it essentially creates a new account on top of the old customer ID info (by matching email address) replacing all of the existing customer info with new, including password.