Snowolf-2 wrote:
It seems that a simple _ fix everything. I'll write on the appropriate www.mediawiki.org page ASAP.
I stumbled across the same problem and the solution is indeed a simple underscore:
Don't write anything like: $wgExtraNamespaces[NS_FOO_TALK] = "Foo talk"; # no underscore
but: $wgExtraNamespaces[NS_FOO_TALK] = "Foo_talk"; # with underscore
See http://www.mediawiki.org/wiki/Manual:Using_custom_namespaces