php mapscript with postgresql 8.1

[Stéphane RIFF]

Trying to run PHPMapscript 4.6.1 against posgresql 8.1, postgis 1.0.4, 
php 4.3.9

All compiles fine without error. But when i launch the application in 
the browser i get those errors :

dl(): Unable to load dynamic library 
'/usr/local/lib/php/ext/php_mapscript.so' - libpq.so.3: cannot open 
shared object file: No such file or directory
*Fatal error*: Call to undefined function: ms_newmapobj() in */var/www/html

*But with postgresql 8.1 the libpq.so.3 doesn't exist it's libpq.so.4

So does anyone get this to work, or maybe postgresql 8 is not supported 
by mapserver now???

Any workaround is welcome

Thanks
Steff