Some 2.4Ghz Cordless phones can interfere with normal operation of a wireless router, especially if the base is close to the router, or one of the computers on the far end of the house.
Sounds like it could be a fault in the EEPROM inside the Battery. The easiest way to fix this is to replace the battery.
Was the cord you bought a replacement adapter for Toshiba or was it a universal deal...if it was a universal adapter it could be the source of your troubles.