function not getting recompiled.

[Steven C. Bagley <Bagley@MIT-OZ>]

In zwei in Release 4.5, site configuration 62, on Lisp Machine Robot-3:

With a function in a buffer, compile it with C-Sh-C.  Then edit one of
the lines of the function, put just that line in the region, and compile
the region.  (This is a reasonable thing to want to do, if that line
sets a global variable and you don't want to have to execute the entire
function again).  Then type M-X Compile Changed Definitions of Buffer.
It won't recompile the function.  This is a wrong, since the function as
a whole has not been recompiled.  Or is this some kind of feature?