Have you got access to php.ini? If so then change these in the file to
Code:
magic_quotes_gpc = Off
magic_quotes_runtime = Off
magic_quotes_sybase = Off
Unfortunatly you can't disable these at runtime using ini_set.
If php is being ran under fast-cgi instead of an apache module, then the .htaccess commands won't work. You'll be able to tell if it is fast-cgi if there aren't any apache sections in phpinfo.