kafka 0.8.1.1 log.retention.minutes NOT being honored

Running a mixed 2 broker cluster. Mixed as in one of the broker1 is
running 0.8.0 and broker2 one 0.8.1.1 (from the apache release link.
Directly using the tar ball, no local build used).

I have set the log.retention.minutes=10. However the broker is not
honoring the setting. I see its not cleaning the log.dir at all.

However when I set the log.retention.hours=1, then it starts cleaning the
log.

When I have the log.retention.minutes set in the server.properties then I
see this logged in server.log:

Š..
[2014-06-27 19:21:06,633] WARN Property log.retention.minutes is not valid
(kafka.utils.VerifiableProperties)
[2014-06-27 19:21:06,633] WARN Property log.retention.minutes is not valid
(kafka.utils.VerifiableProperties)
ŠŠ

I have set these properties too:

log.cleaner.enable=true
log.cleanup.policy=delete

But I see similar warning logged for these properties too.

Regards,
Virendra