libpq.so.4 won't load for postgres 8.1.3, php 5.0.4-5 and apache 2.0.52 on Centos 4.2 [VASCL:A132E50B1DC]

I am trying to get the above combination to work on a Centos 4.2 box.
the Postgres would not load till I put the libpq.so.3 back on.  It would
not load the libpq.so.4.  What do I have to do to get tit to load. I
seem to have all the required software on the box.