I've implemented the vertical scrolling as detailed in the KB article
but I have a problem when scrolling using the SB_THUMBPOSITION. For
example, if I set nMax in the SCROLLINFO structure to 621 and drag the
thumb all the way down to the bottom then nPos (as passed to
OnVScroll) is set to 560. It will never reach the maxmimum value set
in SCROLLINFO. The gap between nMax and the max value of nPos varies
depending on nMax.
Does anyone know why this is happening?