Changes in 8.2's PHP behaviour?

All,

I have a simple web page that inserts data into a table in 8.1.5 using
PHP4. It's pretty amateurish but gets the job done. A few days ago I
upgraded to 8.2 (this is on a FreeBSD system, and I used the port) but
when I tried to use the web page this morning I got errors about:

PHP Fatal error: Call to undefined function: pg_escape_string() in
/usr/local/www/data-dist/some_dir/some_dir/dataInsert.php on line 9,
referer: http://localhost/some_dir/some_dir/dataEnter.php

I'm a pretty poor PHP person, and I think its error messages can be
cryptic, but nothing has changed in this except the version of
postgresql. Does 8.2 handle input differently than does 8.1.x? Is that
where to begin looking? I have seen talk about handling of escape
strings but thought is was 'this way is good and this way is bad' kind
of thing, not a 'this way will no longer work with postgresql' thing.
FWIW a quick pg_dump, a fallback to 8.1.5 and a restore and things work
again.

thanks for any pointers,

r