The official charger does not output 5V, it outputs a higher voltage than that. All devices with the tiny plug will reject 5V with "not charging". The cheap non-nokia usb-> tiny plug adapters are just wired straight with no boost cicuitry, and whether it will work or not will depend on how much higher voltage than 5V your computer's USB outputs, and how inaccurate the voltage sensor in your device is...

There's a document at forum.nokia documenting the voltage and current windows the device will accept. Basically there's a "Not charging" area at and around 5V. Voltages above that are identified as fast charger. Voltages below are identified as "special" charger, and the device will use a charging mode optimized for more stranger sources of power, like solar panels.

So the update to this is that the wall charger did charger the back to full. I'm not sure what drained the battery in the first place and I'm not sure why the two computers that I tried the USB charging cable didn't work but the USB charging cable is working on the computer with that same battery that got charged with the wall charger.

It is interesting that Nokia says that there is a "not charging" area at around 5V yet the USB cable works, at least it is on this workstation and my home computer.

Either the computer that works has particulary strong (too strong) usb power output, or particulary weak usb power output I suspect Nokia's own USB->charging adapter gives more reliable results. It's certainly big enough to fit either step-up or step-down circuitry..