I remember one instance when I was the school supervisor for a place called NCB--not the best place in the world, but pretty decent as far as the industry goes. We got a guy from the U.S. that we hired. Put him up for the visa. Waited a few months for the certificate of eligibility to come through. Then he left the country, got the working visa and returned. And promptly quit, going to work for the place he really wanted to get a job at in the first place, but they would not provide the visa.