It appears to be a common configuration task to include the "." at the end of a record. Google Apps mail configuration uses the trailing dot (which is technically correct, denoting the highest level root for the FQDN but which is left out of many records and left up to the dns resolver to append).
So if you followed the Google instructions you'd get bit by this bug, like this guy and myself were:
Judging by the popularity of that thread it is common enough.
Also you'll see in syslog the bind entries:
dns_rdata_fromtext: <zone>:13: near 'ASPMX.L.GOOGLE.COM..': empty label
zone <zone>/IN: loading from master file <file> failed: empty label