The problem here is probably the rewrite rules; it looks like the site is
rewriting URLs to a form like index.php?title=$1 ... this will break the
parameter when a %26 occurs because Apache forces it to be de-escaped to & for
reasons not known to mortal man.

As a hackaround on the broken rewrite scheme, you could use the patch for Apache
1.3.x we provide which adds a rewrite function to re-escape the & in the title.

See http://meta.wikimedia.org/wiki/Using_a_very_short_URL#Patching_Apache

A cleaner method with an Alias may be preferable, depending on configuration.

kipmaster wrote:

Seems to work as expected now.