Owen Borseth of Domainsite @ IDNForums:

First, the issue is not related to any kind of hardware failure, system failure, or data loss. The reason the domain names were deleted was due to employee error and only affected a limited number of domain names registered on 2006-08-29 or 2006-08-30, depending on your time zone. The affected registrars were Spot Domain LLC, Name.com LLC, and Name.net LLC. 225 domains got deleted and 216 have been restored to date. There are 9 domains that we have not been able to get back.

The 9 names they were not able to get back will probably have been reregistered by other registrants in the mean time. Deletions within the 5 day window after registration do not result in the domain going into the redemption grace period, but the domain is deleted instantly instead.