> Have you checked with the vendor/creator of the library? If not, why

not?

At this point, my FB/SQL knowledge is very low. I want to have a
better handle on what is going on with NULL dates before checking with
the vendor. Also, the most recent rFunc version is dated 2003 and
thanks to some docs Paul V. directed me to, I am beginning to think
that the rFunc problems I am experiencing may be due to the way FB2
handles NULL data. Although I've never tried FB 1 or 1.5, I think that
rFunc works fine with those versions and needs to be updated to work
with FB2, this being my humble opinion of course.