Can't load lib libc.so.5

Hi there,
My postrges 6.1 database has been working fine for a while now.
However, at some point I tried upgrading to 6.4, but failed in loading
all my records in the tables. So I reverted back to the older version.
Now postgres 6.1 works again, but it runs slower and recently I've been
getting
this error.
    date: can't load library 'libc.so.5'
    date: can't map 'libc.so.5'

I chekced the lib and it's accessable and it exists. But what's strange
is that the db still makes selects and inserts, and runs like normal.
Except for that error and it runs a little slower.
Can someone please tell me what it can be and a few suggestions to fix
this error.
Thanks to all who reply.
frank

--
EleComm InterLink Corporation   http://www.elecomm.net
Francesco Fortugno
Internet Support Manager|Systems Analyst
Email: Fortugno@elecomm.net