Problems with 'mp3lame' in 'mencoder'

[das দাশ]

I am facing a problem with '-oac mp3lame' in 'mencoder' options. The
audio is getting full of noise when I am encoding from some VCD or DVD,
or even backup dump of copied-audio AV data. I am not sure if it is some
HW issue, will check it from the SuSE installation on my machine that I
have to keep for the Cannon Scanner, later. Is anyone else facing it?
(Feisty 7.04)

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das