WAL archiving is stuck on an old file that was deleted -- how to get it going again? (8.4.2)

Hi. Need some help getting WAL log archiving going, please.

PostgreSQL 8.4.2

archive_command = '/usr/local/bin/rsync -e /usr/bin/ssh %p
postgres(at)remoteserver:directory/%f </dev/null'

I am able to login to "remoteserver" as user postgres using key-based
authentication (trust relationship exists).

However WAL archiving is failing with errors like:

rsync: link_stat
"/opt/PostgreSQL/8.4/data/pg_xlog/00000001000000350000006E" failed: No
such file or directory (2)
rsync error: some files/attrs were not transferred (see previous
errors) (code 23) at main.c(1039) [sender=3.0.6]
2010-01-06 17:15:13 PSTLOG: archive command failed with exit code 23
2010-01-06 17:15:13 PSTDETAIL: The failed archive command was:
/usr/local/bin/rsync -e /usr/bin/ssh pg_xlog/00000001000000350000006E
postgres(at)remoteserver:directory/00000001000000350000006E </dev/null
2010-01-06 17:15:13 PSTWARNING: transaction log file
"00000001000000350000006E" could not be archived: too many failures

/opt/PostgreSQL/8.4/data/pg_xlog/ exists, but there is no
"00000001000000350000006E" there.

I do have a cron job that cleans files older than 2 days out of the
pg_xlog directory; and the key-based login
was broken for a few weeks (I just noticed).

How do I get Postgres to stop trying to rsync
00000001000000350000006E, and to do rsync all the WAL files that ARE
there?

I've already tried restarting the database but it remembers about
00000001000000350000006E.

Thanks,
Aleksey