As an update, while @JeffSchwenk was very helpful - thanks again, Jeff! - the issue comes down to the fact that this customer has ACS's multi-bin enhancement. Ron Chompf sent me a new file to help fix one problem but that then broke another piece.
BTW, this is for a customer who did NOT choose @haroldwestover's POS solution. Don't forget our webinar which starts in about 15 minutes. Click here to avoid the headaches I've experienced with a different POS system.
https://www3.gotomeeting.com/register/770527262