Please use a correct SOA serial number for your nameserver.
Discussed in the
RFC 1912:
Decimal serial numbers have been officially deprecated in recent BIND versions. The recommended syntax is YYYYMMDDnn (YYYY=year, MM=month, DD=day, nn=revision number. This won't overflow until the year 4294.
So please use YYYYMMDDnn, so for the first entry on the day: 2006052301. For the second change on the same day use instead of 01 a 02!
