bug#3430: 23.0.94; cannot enable two minor modes in .dir-locals.el

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

My LaTeX project setting looks like this:

((latex-mode . ((auto-fill-function . nil)
                (fill-column . 90)
                (mode . outline-minor)
                (mode . longlines)
                (coding . "latin-1"))))

i.e. I want to enable two minor modes for all .TeX files among other
things.

I start with Emacs -q and open a .TeX in that project, only longlines is
enabled. Do you think this is a bug? Thank you.

This is tested on GNU Emacs 23.0.94.1 (i386-apple-darwin9.7.0, NS
apple-appkit-949.46) of 2009-05-23 on 200.sub-75-216-116.myvzw.com

Leo