Maybe you just have to turn it down a bit, I'm not sure. You might give Willard a call. My sense is that he is pretty particular about these setups, so I suspect something is amiss other than turn down the dial.
In my experience with these kinds of burners, a few things come to mind. First if the flame output is obstructed, it can blow itself out. Also, if there isn't enough air (or too much air eg. wind) feeding the flame it may go out. I'm not talking about the burner vent, which is also an air intake, but just having unchoked free flowing air surrounding the circular burner is important. Lastly, if you are running unregulated with high PSI in the line, that could cause a problem.