If you are watching an article called foo:bar, and you then create a custom
namespace called foo: then you are unable to remove the original page from your
watchlist. The page will still show up in the 'pages you are watching' list (in
red), but trying to remove it by selecting the checkbox and clicking 'remove'
does not work.

I have encountered this problem on wikibooks, where I now have entries in my
watchlist for Cookbook:sugar, Cookbook:raisins, etc. that cannot be removed.
Clicking the red links takes me to the correct place in the new namespace, and
the pages have a 'watch' rather than an 'unwatch' tab. I am able to watch and
unwatch the new pages without the phantom entries being affected.

This might be related to bug 3512

Version: 1.5.x
Severity: normal