Banks won't accept them, so it comes up as a "loss", at least it does at the store I work at. It doesn't stop us from taking them (since we're not that anal about it) but it does mean we have to take care to fob it back onto a customer when we give them change. Depending on how strict a store is, yeah, I could see the change being a hassle. And it is not worth the chance of losing your job in this economy.