Terrister

This is what Acer says about the 1640 and bluetooth.

Although there is a button on the
notebook for Bluetooth, the Aspire 1640 models that ship in the US and
Canada do not ship with a Bluetooth module on the motherboard. Therefore it
does not support Bluetooth as it ships. If you push the BT button you
should see No Device on the screen. In order to get Bluetooth, you will
need to purchase a third party device such as a USB to Bluetooth
transceiver, or other external device that provides Bluetooth capabilities.
These type of devices are available at most computer shops that sell
options and accessories for notebook products. We do not plan to implement
an option to install a Bluetooth module on the motherboard.