USB thumb drives or flash drives dont show in Explorer

I put a USB thumb drive in any of the USB slots. The computer makes the noise that somethings connected via usb. But the drive doesnt show up in Windows Explorer.

The same thing happens when I put a flash card in the flash drive. It make the noise, but the card doesnt show up in windows explorer.

Whats more, when I go into Disk Management (right click on My Computer, click Manager, Disk Manager) the USB or Flash drive WILL be there. I can change the drive letter associated with them, but that doesnt solve the issue of the drive not showing up.

I have an external USB DVD drive, and that works fine!!

Any suggestions on where I should start troubleshooting?

 

Alright. It works when the computer is plugged into AC power, but not when its running on battery power.

 

That's strange, mine works fine either way. I have a 8GB SDHC card in and used numerous flash drives w/o the AC adapter connected. Do you have the latest battery? Or have to tried to go to "d:\" in the explorer search bar and see what happens?