Well, WordPress was updated to v1.5.1 last week. The upgrade fixed some problems in v1.5, but (as is so often the case with software) introduced a few minor problems. There’s now an upgrade to the upgrade, and we’re now running on 22.214.171.124. Both upgrades were quite painless.
If you’re running 1.5, there is apparently a security problem which is fixed by the upgrade. You have, as they say, been warned