Still more pg_clog errors

In reference to the pg_clog errors I'm having, I am still looking for
tips or help. Here's the info again:

"ERROR: could not access status of transaction 143934068
DETAIL: could not open file "/usr/local/pgsql/data/pg_clog/0089": No
such file or directory

Now, despite creating an 8k file of zeros (or a 256k file of zeros to
match the others in the directory), when I start the database and try a
vacuum, I get the same message, and upon inspection, the file is gone -
as if Postgres is removing the file.

Any tips or help on what I can do?

steve