Commit a530447a1daa763fa76b884c6eb11847515179f0 deleted some files and now a lot of things aren't translated anymore, including the preferences window. I hope this doesn't stick.
http://lxde.git.sourceforge.net/git/gitweb.cgi?p=lxde/lxpanel;a=commit;h=a530447a1daa763fa76b884c6eb11847515179f0

I'm tired now but tomorrow morning I'll check this better.