Had a similar experience, which normally wouldn't bother me.
Except at my second job (McDonald's), a drive-thru patron was giving me such a hard time about trying to make change from $7.00. This was after a long day of hearing my slightly overwieght wife complain about a deranged man in her parking garage that had a problem with the way she drove, and parked.
I couldn't really hear most of what she was saying however, as there were a number of people at the office having a heated discussion over .9999... equaling 1.