What version are you running? 1.6.3
I have configured ReviewBoard 1.6.3 to use redmine as linked bug tracker.
If I type "issue #81", ReviewBoard links to
http://redmine.example.org/issues/#81
It should, instead, link to
http://redmine.example.org/issues/81
That means, it should strip the "#" sign.
Background: In redmine, issues can be referenced like "fixes #81", "refs #81"... Developers get used to the "#" sign before the bug number. ReviewBoard should also support his syntax.