hi,

i'm experiencing nearly the same problems:

1. wall charger was detected stating "battery is charging". after some time (not moving the device) it wasn't loading anymore. now it's not even detecting the charger when only pluging it in.

2. moving the device or charger cable it's switching back and forth between "battery is charging" and "charger disconnected". and the led is shortly flickering red when doing so.

3. connecting it to my pc via the original usb cable it's loading just fine. even when i move the cable or phone.

4. when loaded via pc cable the battery lasts very long. so it's not a broken battery problem. (right?)

so i thought that maybe the wall charger connector is broken and bought a new (original) nokia charger. i plugged it into the phone and had the same problems as described above.

now i think that my usb port on my n900 is slightly broken.
but then... why is the usb cable on my pc is working fine while both wall chargers are failing?!

next thing i will do is getting a closer look at the connectors. and maybe playing around with them.