I can't hear any sound if I use GNOME on my Debain Sarge 3.1. But, if i switch to KDE i can hear sound if play any audio file.

I got 2.4 kernel on my pc. When i type in >lspci i get my sound card as :
0000:02:0a.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev 04)