The FluPic in my Draco malfunctioned after I lost the silicone o-ring. After reading Kevin's response to what is thought to cause the FluPic malfunction, I'd say this explains what caused the problem in my Draco. Without the silicone o-ring, there is no resistance to hold the head tightly in the on or off position, therefore it will flicker sometimes, on and off, quickly in succession, as the head contact just barely rubs against the top of the battery.
If repeated short, intermittent bursts of power are what cause the FluPic to malfunction, then I think the solution to the problem is to ensure that the flashlight is DEFINITELY in either the on or the off position, and not anywhere close to the on position when not in use.
This means that for lights with screw head caps, that if it uses some kind of o-ring to keep resistance on the threads, make sure that the o-ring is always both intact, and in place. In addition, one should probably unscrew the cap at least half a turn beyond what is necessary to turn the light "off," just to absolutely ensure that the head contact won't inadvertently touch the top of the battery (battery contact), just slightly (enough to turn the light on for a second but not keep it on), i.e. as might happen if it were rustling around in your pocket. Just my theory.
