I have to agree with this as manually entering the 1 cent item would cause an issue like this. The POS system should be smart enough to package the items together or provide the ability to manually package the items.
To add to the Mexx fail thread, I purchased a jacket at Mexx and literally a week later it went on sale so I brought my bill in to do a price protection. Unfortunately, they wouldn't give me the difference as they did not have a price protection policy. The clerk wouldn't even try returning and reselling me the same item so I literally had to return the jacket and purchase the same jacket off the rack. It was a waste of time on my part and a lack of customer service on the part of Mexx. Sad thing is that I'm sure this probably discourages most shoppers and they are able to have these sales without any price protections.