Hi Colin
The bug report was actually created by colleagues at my institution (my vote was the first to be cast!). I just wondered whether there was something we'd missed in the installation, but it looks as though we may all have the same problem.
Our institution has a stand alone wiki that staff can use if they want, however (for one reason or another), this group of users has expressed a preference with sticking with the basic Moodle wiki.
In the absence of a wiki search in Moodle 2.2, I suspect that the administrators are going to end up using the database tool. Unfortunately it doesn't have the level of simplicity that the student wikis would have had, but I'm sure it can provide a workable alternative.
Many thanks for your response!