plpgsql error?

I am running postgres-7.2.1 on suse linux.  I am not in a position to
upgrade my version of postgres at this time.  I have some plpgsql
functions which are called from triggers.  This worked fine in the
past (with the current OS and this version of the database), but today
my functions aren't working (ack!).

I have the plpgsql.so in my LD_LIBRARY_PATH.  I didn't have PGLIB set,
but when I set it to point to the plpgsql.so directory, nothing
changed.

I searched archives and found this error message related to createlang
calls, but my createlang worked without error.  I killed and restarted
the postmaster to no avail.

Is something obvious messed up in my environment?  How can I debug
this?  I get this message when I delete from a table with a trigger
that calls a plpgsql function:

> delete from table1 where value = 'A5';
> ERROR:  stat failed on file '$libdir/plpgsql': No such file or directory

Thanks in advance,

Sarah