DK> The load path shadowing is a red herring: Debian's Emacs package
DK> system is totally contorted and places .elc files and .el files in
DK> different directories.
The Debian AUCTeX package (as of "latest" releases, since 11.82-1 or so,
IIRC) should behave well in this respect: .el files are placed also in
the same directory as .elc files and the load-path should be such that
the directory containing .elc and .el files comes before that the one
containing .el files alone.
However, you are probably right about Debian's Emacs package system