You are clearly on a good track zHO. Pools are exceptionally good at determining what share difficulty you should be receiving. Some pools take longer than others to figure this out. I like to be able to make that decision myself.
My problem was that without suggested difficulty, I would be sent 1K shares for 20-40 minutes until the pool recognized how small I am. (bad things can happen in 20- 40 minutes of not returning a share, zadig, usb, libusb and even more unfamiliar stuff).
Now I can ask it to start at an appropriate difficulty, and I will be returning shares in just moments.
Thanks for the info I've just added it to my cgminer .bat file command line. You're right mine used to start with 1k diff and took a while to come down, it now starts at 30 which was about where it settled at before

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That's very clear now, thank you.