I wondered if a fault has developed on the USB internal controller, but you have a modem running from it, which draws current, usually quite alot so I dismissed it.
Obviously, from your decription of the battery charger not functioning correctly and the USB hub, there may be a fault but without fairly expensive test equipment there is probably no way of knowing.
Have a look here for a selection of internal PCI cards:
USB / Firewire / I/O - USB Cards - Ebuyer