Read another thread at different forum and seems he had the same issue....
My switch has gotten a little flakey (my own fault too, sonofabxxxx). It's still workable, and I don't leave the battery in when I'm transporting this, so its not the end of the world, but just as a warning, if you juice is too thin, it will FLOOD the bowl. I mean DROPS will fill the battery compartment. Especially if you put the pipe in your pocket. Don't do it man. On the upside, thing still kicks so much ..., even with the slightly fidgety switch. I just have to disengage the battery so it doesn't trigger when i don't want it to, no big deal. Might mod the jewelcap to function as a kill switch, depress the jewel to engage the battery, then if the switch is stuck "on" it doesn't matter, automatic evolved into a manual. Works for me!
:EDIT:
Well, the slightly fidgety switch is now behaving 100% as it should. I guess having let it set out upside down over night, and then giving it a quick cleaning cleared the issue up. I'm happy, and sad, all at once. I was rather hoping to need to modify the cap into a manual.