Windows 2000 AS and Solaris9/Bind 9.2.2.

[Dog]

HISTORY:
Windows 2000AS running as primary authoritative name server for 
abcefg.org. <ns1.abcefg.org>

Solaris 9 / BIND9.2.2 running as a slave authoritative name server for 
abcefg.org
<ns2.abcefg.org>

***********************************************************************
Changes are made to the zone file abcefg.org on the Windows 2000AS name 
server ns1.abcefg.org such as zone TTL changing from 3600 to 600.

#dig @ns1.abcefg.org -t axfr abcefg.org
returns all records with a TTL of 600.
; <<>> DiG 9.2.2 <<>> @ns1.abcefg.com -t axfr abcefg.org
;; global options:  printcmd
abcefg.org.           600     IN      SOA     ns2.abcefg.org. 
admin.abcefg.org. 363 900 600 86400 600
abcefg.org.           600     IN      A       172.27.96.136
abcefg.org.           600     IN      NS      ns2.abcefg.org.
abcefg.org.           600     IN      NS      ns1.abcefg.org.
abcefg.com.           600     IN      MX      10 mail.abcefg.com.
host1.abcefg.org.  600     IN      A       172.27.96.160
host2.abcefg.org.  600     IN      A       172.27.96.160
host3.abcefg.org.     600     IN      A       172.27.96.202
*********************************************************************

Changes are NOT fully replicated to the zone file on the slave name 
server ns2.abcefg.org.

#dig @ns2.abcefg.org -t axfr abcefg.org
returns some records with a TTL of 3600 and some with TTL of 600.
; <<>> DiG 9.2.2 <<>> @ns2.abcefg.org -t axfr abcefg.org
;; global options:  printcmd
abcefg.org.           600     IN      SOA     ns2.abcefg.org. 
admin.abcefg.org. 363 900 600 86400 600
abcefg.org.           3600    IN      MX      10 mail.abcefg.org.
abcefg.org.           600     IN      NS      ns1.sbcidc.org.
abcefg.org.           600     IN      NS      ns2.abcefg.org.
abcefg.org.           3600    IN      A       172.27.96.136
host1.abcefg.org.  3600    IN      A       172.27.96.160
host2.abcefg.org.  3600    IN      A       172.27.96.160
host3.abcefg.org.     3600    IN      A       172.27.96.202

*********************************************************************
#ls -la on /var/named/abcefg.org on the Solaris box show that indeed 
some type of zone transfer has occured on the slave.

logs on the slave show that an IXFR started.


Question: Why in the world would only a partial zone update occur.