Lion osx doesn't recognize my external hard disk
I recently installed Lion osx (10.7). But after installation, my external harddisk isnt' recognised by the computer anymore... It's a HFS format disk, and in snow leopard i had no problems with the HD. My time machine partition is on it, along with other important stuff. When i plug it in, it doesn't show on my desktop, nor in disk tools or finder. I've tried waiting for hours, restarting the imac, unplugging the disk etc., but nothing works. The HD is a Western Digital elements disk. Could it be a driver problem?
iMac, Mac OS X (10.7)