removing old installations

[Eric Abrahamsen <eric@ericabrahamsen.net>]

I'm running the Ubuntu repository version of emacs (23.2.1) on Natty. In
the past I've tried compiling both emacs 24 and emacs 23 myself on this
machine, before deciding it was unnecessary and just using the
repository version. As near as I can tell I've cleared the old 24 and 23
installations out of my system, but leftover files are still interfering
with byte compilation in my present system.

Makefiles in external packages like gnus or org-mode set the executable
to "emacs" (ie, no full path). There are no other "emacs" executables on
my path, but still I need to change the makefiles to specify
"/usr/bin/emacs", or else I pick up weird bits from emacs 24, and my
compiled files behave strangely (I can provide more details). Even with
the full path to emacs specified, I get these warnings with each byte
compilation:

Warning: Lisp directory `/usr/local/share/emacs/23.2/site-lisp' does not exist.
Warning: Lisp directory `/usr/local/share/emacs/site-lisp' does not exist.

All my site-lisp directories are under /usr/share/emacs or
/usr/share/emacs23, and I don't know what configuration or startup files
are telling it to look under /usr/local/share.

Given that no other "emacs" executables are on my system (at least, to
the best of my knowledge, and I spent a while rooting them out), what
other leftover files could be confusing my present installation?

Thanks!
Eric