strangely, Gavin, my sqai body has just started to do the very same thing. I've tried new batteries, with no difference. The shutter is supposed to default when the batteries run out, but even that doesnt happen. I've tried using different lenses too as the shutter is in the lens, but to no avail.
So I cant help, but I'd also be interested in other's thoughts. I'm probably going to send the body for repairs soon, so if I find out what has gone wrong I'll let you know.