You don't need to OwnBlitter(). Make sure that you're blitting from and to
RastPorts that have been initialized properly, and have real BitMaps and
rasters attached. I never use the 16-bit integer model on Manx 3.6 or
Lattice 5.05. Thus, I have never had to worry about whether I'm passing a
short or a long in the arguments, they are always promoted to longs. Just
for kicks you might want to compile with the +L option and link with the
c32 library.
This call works fine. Perhaps a clip from your code here would help (you
didn't already do this, did you?).