There are two updates available now:

1. If if you are upgrading from either Drupal 4.5 or CivicSpace 0.8.0.x to Drupal 4.6 or the equivalent CivicSpace version.
2. If you are running the pre-daylight savings time supported 4.6 version of event. If you were running v4.6 event without
   a event_timezones.inc file in the event directory, this is you. You can also check to see if your event table has a 'tz' field
   instead of a 'timezone' field.

To update do the following:

First upgrade to Drupal 4.6 with event 4.6 and read the upgrade.txt that comes with it.