Enabling WDDX

I run websites on server farms - and am usually faced with difficulties as a result of the PHP configuration being at the whim of the ISV staff - especially when version upgrades are made - they frequently fail to include all the needed -with- and -enable- statements. If (my assumption) WDDX is now 'native' to PHP --- is there a way to have it always included in the build, as opposed to rely on it being included in the configure command line? Else is there a way to allow it to be turned on through either the php.ini file or though the .htaccess technique? Caveat - I have tried to use both php.ini and .htaccess to asccomplish this ((on v4.04pl1)) but was unsuccessful. If should have worked the please describe what I _should_ have done -or- if it's a prob with that 'version' only please advise. Many thanks, Tom