[rt-users] IS NULL vs = 'null'

[Tony Bowden]

We finally managed to upgrade to 3.2

And, now all my bookmarks are broken :(

So I tried to rebuild all my searches. But some of them I can't get to
work at all.

In particular, we have a custom field for Client. And I had a search
that lists all the tickets that had no value set for this.

However, when I try to build this query now, it always returns 0
results. It appears to be turning 
  Client is (no value)
into
  'CF.Client' = 'null' 
rather than
  'CF.Client' IS NULL

Am I missing something obvious, or is this a bug?

Tony