Problem with use of MRO (maybe)

["Owen Davies" <owen@xxxxxxxxxxxxx>]

Hello, all, and happy holidays.

I've finally gotten around to looking at the techniques offered in 
"Street Smarts," by Connors and Raschke.  To make things
easier, I am coding indicators to flag each setup; they read -1
when the technique offers a potential sale and 1 for a possible
buy.  (Using Supercharts, it isn't possible to code most of these
methods as systems, and I'm too cheap to buy their disk.)

My (first) problem has come up in looking at their "Turtle Soup"
trades.  The idea (for those not already familiar with it) is to fade
breakouts of the 20-day range if the price starts to pull back,
provided the previous 20-day high or low occurred at least four 
bars ago.  So I want an indicator that marks 20-day highs and
lows occurring at least four days after the previous one.  I tried
the following:

Iff(Low = Lowest(Low, 20) AND
    MRO(Low = Lowest(Low, 20), 21, 2) > 3, 1, 0) +
    Iff(High = Highest(High, 20) AND
    MRO(High = Highest(High, 20), 21, 2) > 3, -1, 0)

It almost works.  Not quite.  When it flags a bar, it seems to be
correct.  But it misses bars that should be marked, and I have 
no idea why.  Can anyone tell me what I'm missing?  Or suggest
a better way to accomplish this?

Incidentally, this is not a one-shot.  I seem to run into this sort
of problem whenever I try to use MRO.  Could this function be
just a bit buggy?

Thanks for whatever help you can offer.

Owen Davies