Yesterday, the Tank007 E09 I had purchased a couple of weeks ago from another BLF member died.
My first thought was a battery problem, but I swapped the battery with a known good cell and it still wouldn't work. Based on other's reports here, I had kept the head assembled to keep the insualation intact. Since the light wasn't working, I disassembled the head; with the reflector removed the light works perfectly. It looks like Tank007's insulating reflector glue was either a bad idea or poorly implemented on these lights.
I did take advantage of this opportunity to clean the fingerprints from the inside of the lens and the debris from the emitter dome while I had the light apart. I was able to clean the dome by wiping it very gently with a Q-tip and isopropyl alcohol. I know these domes are fragile, but mine was very dirty to start with so I took the risk. Now the dome looks perfect, no scratches, smudges or dirt.
I have some Kapton tape at home, so I guess I'll be making a new insulator for this light this weekend.