I do not know if it is really a bug or a feature :).
The problem is
that when i try to evaluate region it succeeds only if
point is
greater than mark (or to put it another way: start <
end). Otherwise I
get "Invalid search bound (wrong side of point)"
message and no
evaluation occurs. I have found it very annoying and
very easy to fix,
so here is a mini-patch. I am using ilisp with FSF
emacs 21.3.1 and
CMU lisp 18e.
mini patch, which adds region bounds checking to eval-region-lisp