[gmarco]

Thanks very much for you clues.

-- [...]
RemGank_conf_scrollFrame:SetScript("OnVerticalScroll", function(self, offset)
    FauxScrollFrame_OnVerticalScroll(self, offset, BUTTON_HEIGHT, RemGank_ListFrame_Update(self))
    FauxScrollFrame_OnVerticalScroll(self, offset, BUTTON_HEIGHT, RemGank_ListFrame_Update(self))
end)

It works and fixes the wrong offset problem. It is not a beautifull solution, but at least it is a working one :-)

Thanks again.