TEAC USB HS- Card Reader disappears

I have a Dimension 9150 with a TEAC USB HS Card reader built in (factory original). This device is listed in my Device Manager as four entries: TEAC USB HS-CF Card USB Device TEAC USB HS-MS Card USB Device TEAC USB HS-SD Card USB Device TEAC USB HS-xD/SM Card USB Device This device will periodically disappear from both My Computer and the Device Manager. It can happen in as little as three minutes from computer boot, to several days from computer boot. Any ideas? Any updated drivers available? I can't seem to find any.