How to remove sound artifact during VHS-DVD conversion?

[Macmon]

I am trying to convert my VHS medical review sessions to digital then DVD.
My set up is my VHS player --->Sony minidv HC-40 videocam ---->120 meg External HD (FW)-----> ibook G4 (imovie) --->iDVD

I am able to convert the video without problems but what I noticed is that the sound has an artifact wherein I hear "clicks and pops" aside from the expected voice of the lecturer. If I listen to the VHS tape, there aint any. If I convert from the the minidv sony to the ibook, it has good quality.

My question is that where is the probable problem that occurs with my setup?
Is it the cable from the VHS to the Sony minidv? it uses its own RCA-sony cable.

Any suggestions would be appreciated on how to remove those sound artifacts.
Thanks