I read your comment on Barry's blog:
I would like to add that this is not the case on my box. I had xdialog.mo in /usr/share/locale/nl/LC_MESSAGES only and Xdialog ran translated.While talking about momanager...
... we have found out that Xdialog uses Xdialog.mo in /usr/local/share/locale
Only after that did I add the .mo to /usr/local/share/locale...
I just checked, by removing the .mo from /usr/local/etc and xdialog is still running translated.
I think rodin.s gave the second location only for Slacko.
Hope this is useful