PROTOOLS LE DIGI003 10.4.10 OS X J-8 pops and blocks ALL

[asle]

Hi

My Jupiter 8 pop's and the blocks all sound to the master. If I Bypass it - the sound off  all tracks (except that with the J-8 natually) kicks in again (with a pop) and if I turn it on again the same thing happens. A pop and the all in quite again (the J-8 is UNmuted and all sound stops)


What can cause this.  please help


Cheers

ASLE