Kindle Crash fixed (early model with buttons)
 

Problem solved now, but I thought I'd document it because the answer is not obvious.

My Kindle wifi went down and the battery life diminished appreciably. Efforts to reset using the 'press the button for 20 seconds' reset were not helpful. On-line research did not help. Eventually I ordered a new one.

Then the Amazon fix-it thread provided a solution:

home>menu>settings>menu>factoryreset

It was the second use of menu that wasn't obvious.

Factory reset got the wifi working again, and now battery life seems to be ok.

(Applies to early Kindle with 5-way button operation)

So how does the new one compare with it? :}

Haha - fixed it just in time to cancel my Orinoco order. :8