can be USB, can be if you have been messing around with deeper settings in power kernel or have been messing around with nitdroid or other?

if this is something that has suddenly begone to happen then 99.5% it's the USB, now you have following choices:

- Keep using it until it breaks off and do the whole warranty thing, and be VERY lucky to get a new N900...

- Goto my thread and fix it your self, if charging problems have accrued then you will need to do the solder down and see if you are lucky and reheat/resolder the pins from the USB.

Again link in my signature