I've noticed that my mini yellow RSK has a clicking sound to it when I've picked it up. I can shake it and the clicking continues. The only time I can't hear the click is when the blade is open.

Does my knife need professional help?

Have you tightened the torx screw the blade pivots on?

It's not loose enough to where I can hold the pivot with my finger and thumb to stop the clicking...and...silly me, I have no tool to check that with at this time...have to work on that.

You can buy a set of those screwdrivers pretty cheap at Wal-mart

My full size RSK rattles like that. You might try tightening the screw, but I found that if I tighten mine enough to eliminate the click then it interferes with the opening of the knife. I just live with it. It's more of an annoyance than a problem.

There is a fine line between just right and too tight. If you tighten a little too tight don't worry it will loosen after opening it a few times.

Try some powdered graphite as a lubricant.