We simply
don't want our regular users to be able to change the
Sidebar at
all - is this possible?
Pages in the MediaWiki namespace (including MediaWiki:Sidebar) can
only be
edited by users with the editinterface right; by default, that's just
admins. Have you checked whether other users actually can edit it on
your
wiki?
My humble apologies for not completely testing this. You are right, and I
have located documentation to back this up. Thanks for the heads up :)
Cheers,
Michael Hutchinson