Repeating Events: excluding dates doesn't stop the event from being created

When creating an event it is possible to set the repeating options for that event, and as part of that, to exclude one or more dates form the repeating pattern. When saved, CiviCRM presents a listing of the events/dates on a confirmation page. These match the requirements as specified. However, when confirmed, CivicRM creates the events and ignores the excluded dates, creating events for those dates as well.
I'm seeing this happen on a 4.6.2 installation. Tried to replicate it on the d46 demo server (reportedly running 4.6.4) but that crashed with an unknown DB error.