pg_dump error

I'm rather new to database stuff. I've been using postgresql for a
couple years, but that doesn't mean I understand what I'm doing. I have
simply followed the "HOW-TOs". But now I think I'm about to learn a bit
more about the inner workings...

Last week my cron-triggered system-backup began reporting odd errors.
They were block device and limited to just the one partition so I ran
fsck.

Oh, this is a Pentium-Pro based computer running Debian with a 2.4
kernel, SQL-Ledger 2.2.6 as my frontend, postgresql 7.2.

So on with the story. fsck found a number of problems and I let it fix
them all. No, I don't remember what the problems were. *grimace* The
system backup is no longer yelling at me - but now my pg_dump is!

It says:

pg_dump: NOTICE: RelationBuildDesc: can't open pga_images: No such file or directory
pg_dump: SQL command to dump the contents of table "pga_images" failed
pg_dump: Error message from server: ERROR: cannot open pga_images: No such file or directory
pg_dump: The command was: COPY "pga_images" TO stdout;

Also, the Debian do.maintainence script is reporting:

NOTICE: RelationBuildDesc: can't open pga_images: No such file or directory
ERROR: _mdfd_getrelnfd: cannot open relation pga_images: No such file or directory

So I tried:

$ /usr/lib/postgresql/bin/vacuumdb -z -d mydata
NOTICE: RelationBuildDesc: can't open pga_images: No such file or directory
ERROR: _mdfd_getrelnfd: cannot open relation pga_images: No such file or directory
vacuumdb: vacuum mydata failed

Okay, now I'm stumped! Since I don't even know what "pga_images" is for
I don't no how much trouble I'm in! Should I worry? Am I doomed? Can it
be repaired? Will my computer explode and infect my neighborhood? (Have
I used too many question-marks?) Nothing else seem to be broken, just the error messages about pga_images..

Philip,
a bit worry about my database...