apparent wraparound

After a system crash, postgresql 8.1.4 restarted but reported that I
have an apparent wraparound:

2006-07-13 14:03:40 PDT [10092] LOG: database system was interrupted at 2006-07-13 13:22:19 PDT
2006-07-13 14:03:40 PDT [10092] LOG: checkpoint record is at 1DD/26283E18
2006-07-13 14:03:40 PDT [10092] LOG: redo record is at 1DD/26283E18; undo record is at 0/0; shutdown FALSE
2006-07-13 14:03:40 PDT [10092] LOG: next transaction ID: 169855318; next OID: 787933
2006-07-13 14:03:40 PDT [10092] LOG: next MultiXactId: 5475264; next MultiXactOffset: 13765525
2006-07-13 14:03:40 PDT [10092] LOG: database system was not properly shut down; automatic recovery in progress
2006-07-13 14:03:40 PDT [10092] LOG: record with zero length at 1DD/26283E68
2006-07-13 14:03:40 PDT [10092] LOG: redo is not required
2006-07-13 14:03:40 PDT [10092] LOG: could not truncate directory "pg_multixact/offsets": apparent wraparound
2006-07-13 14:03:40 PDT [10092] LOG: could not truncate directory "pg_multixact/members": apparent wraparound
2006-07-13 14:03:41 PDT [10093] [unknown]%[unknown] LOG: connection received: host=[local]
2006-07-13 14:03:41 PDT [10093] postgres%postgres FATAL: the database system is starting up
2006-07-13 14:03:41 PDT [10092] LOG: database system is ready
2006-07-13 14:03:41 PDT [10092] LOG: transaction ID wrap limit is 1243594092, limited by database "csb-dev"

This is from:
PostgreSQL 8.1.4 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC)
4.0.2 20050901 (prerelease) (SUSE Linux)

I'm using autovacuum and it ran around 13:15 on database csb-dev. I see
no errors in the logs and therefore assume that the vacuum was
successful.

There are two files left in pg_multixact:
-rw------- 1 postgres postgres 16K 2006-07-13 14:13 pg_multixact/members/00D2
-rw------- 1 postgres postgres 144K 2006-07-13 14:13 pg_multixact/offsets/0053

The system crash occurred during scsi rescanning that was initiated by
an admin. The machine has been extremely stable otherwise and I have no
reason to suspect hardware flakiness.

In
http://www.mail-archive.com/pgsql-general(at)postgresql(dot)org/msg76635.html
Tom Lane implies that I can probably ignore these messages.

So, the 64K questions: Can I really ignore this? Is there anything I
can do to ascertain whether it's a false alarm?

Thanks,
Reece

--
Reece Hart, Ph.D. rkh(at)gene(dot)com, http://www.gene.com/
Genentech, Inc. 650-225-6133 (voice), -5389 (fax)
Bioinformatics and Protein Engineering
1 DNA Way, MS-93 http://harts.net/reece/
South San Francisco, CA 94080-4990 reece(at)harts(dot)net, GPG:0x25EC91A0