I took my light apart today (same type as JamesM's) in an attempt to seal where the cable enters the casing. Would have just sealed it from outside but the 2 inner cores of cable were visible where they came out the handlebar mount. Also wanted to check interior for swarf, thermal paste, etc and from something I read, I wanted to secure a coil that is part of driver.
Mine also has the 2 lights in switch lit at same time, hadn't noticed before as being colour blind I couldn't tell what colour the switch button was.
Removing the driver on it's brass slug from the LED mount was a pain in the arse, once done was able to use hot glue to hold coil in place. Tried to seal/hold cable in place where it enters the LED mount. Made it feckin' hard to put it all back together but succeeded in the end. The LED star did appear to have thermal paste/glue holding to it's heatsink. The o-ring seal at rear of reflector when removed turned out to be barely 20mm in diameter and had been stretched in the extreme to fit in groove in reflector. No wonder it looked a bit iffy, not good.
Put some hotglue in hole for cable, to seal it, before refitting handlebar mount again with glue under it as threads for wee screw are a tad effed. Since I only unscrewed it, it must have been done on first assembly
Anyway the threads that are left seem to be holding it OK with the help of the hotglue. Although the light gets hot when it's been on for a while it wont'd get hot enough to melt glue.
Sealed the battery by putting it in a balloon left over from Halloween. Cut half the neck off then stretched it over battery, used one of those wire-twist poly-bag closures to keep neck closed.
I've not been able to compare it to other eBay/DX lights but it's not as bright as I expected from what I've read on forums.
Might buy another light from eBay but will get one of the ones described on DX as "assault" as the reflector is different shape and there's only one o-ring needed to seal bezel that holds lens/reflector in.