ISPCONFIG SUPHP and OPEN_BASEDIR

I'm a system administrator of a linux hosting server (ubuntu 8.0.4).
I chose to adopt ispconfig together with suphp.
I had PEAR not working, and in phpinfo() the variable open_basedir pointed only to the root of the hosting space (something like /var/www/web7).
I needed to add /tmp and /usr/share/php to each open_basedir vhost, but with suphp you use php CGI, so you can't use php_admin_value.
I was going crazy too to find out where open_basedir was set: not in Vhosts_ispconfig.conf, not in php.ini ....
I found the way out looking at /etc/suphp.conf at the line:

x-httpd-php=php:/home/admispconfig/ispconfig/tools/suphp/usr/bin/php-wrapper

So I took a look at php-wrapper, and there it was:

exec php-cgi -d open_basedir=${BASEDIR} -d upload_tmp_dir=${TMPDIR} -d session.save_path=${SESSDIR} -d safe_mode=${SAFE_MODE}

where BASEDIR=`dirname ${DOCUMENT_ROOT}`
So, if you have the same problem as I, define a new variable:

OPEN_BASEDIR="/tmp:/usr/share/php:"${BASEDIR}

and put it in the above line as follows:

exec php-cgi -d open_basedir=${OPEN_BASEDIR} -d upload_tmp_dir=${TMPDIR} -d session.save_path=${SESSDIR} -d safe_mode=${SAFE_MODE}

NOTE: if you successively upgrade ispconfig package, remember to re-apply the above patch.