wierd sound on when listen to mp3 or avi

[mke]

hello,

i have a small problem with the sound on my system. whenever i play a avi, or an mp3 with winamp and the system is busy gets busy at that time, the sound is heard as if it is slowing down and kinda like passing through a phaser filter making it sound digitaized or something. what is that? this wasnt happening two days ago and i have not installed anything new.
cpu amd xp2400, 1Gb ram pc3200, ati 9000 pro 128mb, maxtor60gb. though i dont think its the specs. anyone has any idea to this???

 

[mke]

anyone that can help? i dont understand why this is happening. i mean the sound kinda decreases spead like on vinyl with effect and returns back to normal. anyone?