Error in installing gstreamer0.8-mad

[W.H. Kalpa Pathum]

    I installed UBUNTU 5.10 "Breezy Badger" on my PC and I couldn't play 
MP3s. I found that gstreamer0.8-mad should be installed. So I downloaded 
gstreamer0.8-mad (I downloaded this file in a Windows computer and copied it 
to UBUNTU) and in the install process of the file the follwing errors were 
occured.

OIL: ERROR liboiltest.c 247: (): illegal instruction in idct8x8_s16_mmx
OIL: ERROR liboiltest.c 247: (): illegal instruction in idct8x8_s16_mmx

    When I try to play a MP3 in Totem Movie Player it said "Could not open 
resource for writing".

    What is this ? How can I make MP3s run in UBUNTU.

    Please reply me to as soon as possible.

W.H.Kalpa Pathum