My Treo 800w is sitting on my desk, plugged in, and not charging at all. Turns out I'm not the only one -- it's a common issue when the battery on the Treo 800w gets really and truly drained. Fortunately, aixguru in our forums has discovered a patch over on Palm's site. Go grab it and install in on your Treo 800w. Here's the score:

USB: If your device fails to detect any of the in-box USB accessories such as the power adapter, headset or sync cable, this update will resolve most of the detection issues.
Battery charging: When plugged into the charger, the device may not charge a completely discharged battery. This scenario is most likely to happen if you leave a dead battery for a few days before trying to charge it in the device.
This update is highly recommended for all Treo 800w devices.

We agree. Now all I have to do is figure out how I'm going to apply the patch given that my Treo isn't recognizing a charger at all. My plan: the Treo 800w shares the same battery as the Centro -- time to swap.