Register Fire 

Any situation that interrupts the normal flow of a checkout line — resulting in the cash register and/or cashier metaphorically bursting into flames. Causes include employee incompetence, consumer ignorance or (in rare but highly disruptive circumstances) an actual technical malfunction. Register fires typically strike without warning, usually during peak shopping hours. While a shopper can sometimes spot a register fire in progress and avoid the affected checkout line, most register fires are impossible to predict.

Don’t get in that line. Looks like a register fire.

Some idiot tried to return a CD without a receipt and started a register fire.

Her credit card got declined. Register fire! Abort!

Register Fire by GeyerCom August 14, 2008