This should be made a sticky under Reader Troubleshooting.
Using PSP charger is the easiest. I have had Motorola phones/Sony Ericsson/WM devices/Blackberry devices that refuses to charge via USB from certain laptops/Wall plug usb chargers. Sometimes it is just the USB cable (yes, it is dumb, but I have no real idea why). The same failed device can work on another laptop too (But that is not the solution the user looks for)
ps. I work in an IT dept, hence my constant exposure to these gadgets