Noise problem - Sound sample included

[bjoo]

Hi.
I'm a newbie home engineer.
I'm not sure that this topic is about masteing, but it occurs when I tried to apply some bus compressing.
Here it is.

http://www.nelm.co.kr/bjoo/ThroughTW.mp3

Yeah It's a number from Metal**ca. I played all the parts by myself.
Anyway, can you hear the clicking noise from the guitar intro?
Obviously, it doesn't clipped or peaked at that point, and when drum kicks in, it sounds OK.
Do you guys have any idea that where the noise is coming from?
I can remove the noise by lowering down the level, then the whole mix will be too quiet..

I use nuendo and timeworks mastering compressor for final limiting.

Cheers,