Hi Sara,
What you need to do is to
1) dowload the deployer from here: http://downloads.jboss.org/snowdrop/1.1.0.GA/jboss-spring-deployer-3.3.zip
(the main download page is at http://jboss.org/snowdrop/downloads.html)
2) extract it into $JBOSS_HOME/server/default/deployers
(the whole procedure is described here: http://docs.jboss.org/snowdrop/1.1/html_single/index.html#d0e150)
Hope this helps,
Marius