I don't know that this would be the best course, just throwing it out there, but what if you demanded the accountant cut you a check immediately? Like, "I need my back pay today or I won't be able to work effective immediately." You could even suggest that the owner write you a personal check and get the money from the business later. Or that they call you when they have your money ready, but you aren't coming back until they do.

It only works if you are acting in an essential role and you are willing to give up the job and reference if they don't bite. It may not be the best course of action, just something else to consider.