Thanks to macgyver35, I managed to repair my EA4W tonight.
When I got home today, parts were in my mailbox, from:
Hong Kong Dafang Logistics Limited
Nitecore
P.O. Box No. 68107
Kowloon East Post Office
Hong Kong
It was a bit of a challenge getting it apart and back together, but it's working again. The bezel seems to be sitting a bit higher, so I'll keep an eye on it.
For me, it wasn't a melted or bubbled switch cover. It just came apart, "rubbed off" about the time I started using the nice custom holster from Thor's Hammer. For a while, I just kept Scotch tape over the button and used the light that way. Eventually, the tape got a bit too tired before I noticed and replaced it. As I was walking into a store one evening, I lost the little black plastic piece from the center of the switch.
i contacted Nitecore via email. After some back & forth and me explainng I had mail ordered the light, they sent me some parts, including the actual switch (which I didn't need). The possibility (and possible inconvenience) of mailing the light back to Hong Kong was mentioned, but I decided to try fixing it here first.
i think Nitecore may have changed more than the switch cover. The little round black plastic part that has to pass through the clear plastic part to reach the switch did not fit (either the clear piece they sent me or the one I had). I had to carefully enlarge the hole in the clear piece to just a hair over 9/64" but it worked out fine.
I am glad to have the light back in service. It's my daily "big" light at work, and I use NiMH batteries.
Now to contact 4 Sevens and see about getting my Preon II fixed so I can stop carrying my wife's Preon II for my daily "small" light (mine acted up, but hers and two others I bought for co-workers have worked fine).
I guess if I truly want reliability above all, I should save up and buy HDS. But I do like this EA4W.