SOA Serial Stays 0 With GMySQL Backend

[anon]

I have an SOA record for test.com as:

ns1.domain.com. hostmaster.domain.com. 0 10800 3600 604800 3600

According to the documentation the serial number should be the highest change_date out of the records for the domain. However, I always get the serial number 0.

test.com.		3600 IN	SOA ns1.domain.com. hostmaster.domain.com. (
				0          ; serial
				10800      ; refresh (3 hours)
				3600       ; retry (1 hour)
				604800     ; expire (1 week)
				3600       ; minimum (1 hour)
				)
test.com.		3600 IN	A 127.0.0.1

I am running version 2.9.22 on Ubuntu 10.04 server, 64bit.

[peter]

The documentation never claimed this. However, it was easy to misread it as such. Revision 2290 adds this feature.