"GG" sound and reading not smoothing

Nice to meet you all,

I am the newbie who come from Hong Kong, I am using LG 4163B DVD writer. I bought it for 1 and half months. Recently, I don’t know why my writer have some “GG” or “tak tak” sounds after I insert the DVD. That problem also occur including I try to play the
movie(rmvb file)…My habit is that I always skips the video to watch…So I would scroll the time bar to suitable time…But I found that when I scroll the time bar…It seems not smoothing…On the other hands, I try to copy the file directly to harddisk to test…but it is smoothing…
Does the seeking time of writer is low?
Anybody know why?
Disk Problem or writer problem…?