PHP and libpq version question

Hello,

I have compiled an apache/php rpm package for my servers on a box which is running postgresSQL 8.1.9.  On a server
running8.1.0  I get the following when trying to start apache. 

Cannot load /opt/apache/modules/libphp5.so into server: /opt/apache/modules/libphp5.so: undefined symbol:
PQescapeStringConn

Is this because of the version difference?

Thanks,
Dustin Butler
Intrcomm Technology