Thank you Si! No, I used a Simple Media 128CF media card that came with my second SL-5500, my other flash was with a PNY 128CF.
I (just now) opened a new PNY 128CF card and copied ospack to it, and it flashed the Z straight out of the chute. Yeeha!
What threw me, was on the first attempt, both lights stayed on for about 10 minutes till I finally said Hell with it and hit reset. After that the lights would go out as previous described (as soon as I released the " C & D " keys.
Thanks again mate, my head got totally bent out of shape during the exercise, not condusive to logical thought.
Cheers, Joyeux Noel, Lou
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Are you using the same CF card