Thanks for the responses guys. I've considered all you've pointed out except for: Paul's Dying Pram battery argument would sound pretty compelling if the problem had only just started to appear, but it's happened a couple of times some six and twelve months ago. I'll also trash my sound prefs and zap the pram tonight and see if it happens tomorrow morning. It never happens after a reboot. Only on starting up from cold. So maybe it has nothing to do with drives? Roy P