New autovacuum messages in postgres log after upgrade

During a maintenance window, we upgraded our systems to Postgres 9.0.13
from 9.0.3 running on FreeBSD 8.1 amd64.

When we restarted the postgres server, I notices, and continue to
notice, a recurrence of messages in the log.

2013-09-16 21:15:58 MDT LOG: automatic vacuum of table
"ishield.public.tbltmptests": could not (re)acquire exclusive lock for
truncate scan

2013-09-16 21:15:59 MDT LOG: automatic vacuum of table
"ishield.public.tbltmptests": could not (re)acquire exclusive lock for
truncate scan

2013-09-16 21:16:00 MDT LOG: automatic vacuum of table
"ishield.public.tbltmptests": could not (re)acquire exclusive lock for
truncate scan

The tables on which I am seeing this messages are essentially temporary
work tables into which we insert records, which are processed by
triggers, and then deleted.

Performance of the system does not seem to have been affected by the
upgrade.

Is this simply caused by a higher level of verbosity in the autovaccum
logging, as a result of the autovacuum fix in 9.0.12?

I did notice that while previously I had issues with vacuum full not
being able to run due to not finding an entry in toast tables, this
appears to have been resolved.

Thanks in advance,

Benjamin