Sending tracks to Bus - When nuting Bus tracks are not muted?

Hello Sonar people!
 
Let me explain myself better :)
 
Let's say I have 3 guitar tracks in a project, I create a "Guitar bus" and send them all to that bus, with the level all the way up, when I mute the BUS however, the original tracks still plays, which tells me that whatever I put in that bus, as far as processing, is not taking effect as it should, as the original tracks are always "mixed in" with the BUS.
Am I using this incorrectly? I always thought BUS'es were meant just for that? So you could send multiple tracks there and do a "master" processing on all of them? But if the original tracks are always being played I'm not getting what I need, which is just the processed signal...
 
Help me, Oh wise people! :)