Ok, this is interesting. My headset pairs, connects, then drops. If I open my sound prefs and select the headset, it boots and I have sound. As long as I do not close that dialog (this trick from another thread), the headset remains active.
Clearly you need to have activity to the device to keep it on line - makes sense, to save power, though it apparently has "failed". The device bounces back in to try to cennect, then out again.
Fun part: if I open Skype and dial someone, the headset kicks in. So for the moment I am treating it as "on demand", though it is a little unnerving. Certainly don't like this pop-in-pop-out behavior. Maybe a bit of config I haven't read yet, or an OS bug.
A Traud mentioned some "force visible" feature of some headsets. While his posts are frequently incomplete, and I would not be very happy with him as my Helpdesk Attendant (sorry, Traud, but take a good look at what you're dishing out: what's with this Bluetooth Updater that is supposed to be run even if you are on new systems? Sorry, baby, strike two), still it is worth looking into, perhaps the headset is "proactive" and maintains its own connection?
I had a high-end motorola which I believe had this ability. I traded it in for this Plantronics Voyager 510, which is uncomfortable and can't do this nifty trick - maybe I'll switch back.
Let us all know if you find anymore data.
Thanks