firefox-toolbar.png is not used anymore (see bug 299554 comment #12). Removing this from l10n cvs causes nightly build to break. It could be the same for the other removed .png files. Builds shouldn't break while removing these files.
Build log : http://tinderbox.mozilla.org/showlog.cgi?log=Mozilla1.8-l10n-fr/1157316780.11978.gz Adding the file back to the cvs make the tinderbox greening
Did you also removed the corresponding line in extra-jar.mn?
(In reply to comment #2) > Did you also removed the corresponding line in extra-jar.mn? Oops. I was sure I did, but it's not the case. It was probably another image. I guess I can close this bug as invalid...