My SRT does this too. It does kind of bother me, it's almost like it has a bigger cam or something. I will however look at those hoses.

I also have a highly modded Buell motorcycle with a huge cam, and you could make milk shakes on the seat when it idles It will actually vibrate accross the garage floor when it is in high idle mode. (my wife loves it ) So I guess compared to that the little shake in the idle of the SRT is nothing.