Affiliate Plugin causes an error

My setup is 3.01 + Multi-db + Supporter and now I want to add
the Affiliate Plugin but it gave me an allert.
Fatal error: Call to undefined function update_usermeta() in /var/www/web2/html/wp-content/mu-plugins/affiliatelite/classes/affiliateadmin.php on line 390

I need your help.
Thanx in advance