Window drop shadow in Gnome
 

Hello :-)
I was trying to enable window drop shadow in Ubuntu Dapper Drake.
I added the "Extensions" section in xorg.conf like i used to do in slackware (KDE). Now i cannot find any place to enable the drop shadow. i have seen some screenshots of gnome that shows drop shadow. I have searched for the opetion but failed to find in in ubuntu (GNOME). i would appreciate some help on this. Thanks.

Are the drop shaddows seen in the screen shots not xgl?