I plugged a USB wall charger (for my Blackberry) into my 505 Reader to recharge it from 2 bars. The screen indicated presence of a USB connection (USB plug icon in middle and on top right, 'USB connected' at the bottom). But, this drained my battery to 1 bar, and then 'low battery' status in about an hour. I thought the 505 could be *charged* via USB, not drained!
Any explanation for this? It's a standard USB wall charger, and it charges my phone just fine.