My experience so far is that the Palm WiFi card is incompatable with MathLib, a very common utility that is bundled with lots of third-party programs. I had alot of Fatal errors at first, then I did the hard-reset too- lost everything.
Heres what I did different--
I reloaded the WiFi software first, into the re-virgined E2, this time I had the charger plugged in so the Palm's circuits were supplied 100% full of power.
The Palm hotsinc software put back most of what was lost (contacts, notes,memos, etc) great!
Then checked the Info screen for any programs recovered, there was sollitare and MathLib there again, so I deleted sollitare and mathLib from the device. (the E2 does not use these programs in it's brand-new state) I also went into my computer's Windows;Programs; Palm; Backup: file and deleted MathLib so the Palm Desktop wouldnt recover it each time I hotsinc'd.

So what did I do so I could use the programs that need MathLib? Load the programs on the device, but put MathLib on a SD card, that way it is isolated on the SD card, the programs that use it will still run, and when you change cards to put in the WiFi card- MathLib is gone. :)
Just remember you can't run those dependent programs until you put the Mathlib SD back in.

So far this has worked, no more Fatal errors. However, there are other causes for errors with WiFi, but I hope my experience with MathLib, and my isolation trick helps others.