Hi Erik.
It sounds really unfortunate indeed. Thanks for all the troubleshooting you've done in advance, I really appreciate it!
It seems like the only thing left for you to try is to check if the same thing happens with a different USB cable and a different computer. The drive is recognized indeed, but if the different cable/computer does not help the reason for this is that the files system might have become corrupted. Actually, there's no file system listed (not even a RAW one).
If you have data which you need to recover, I'd advise you to try and access the drive via Ubuntu Live USB/DVD, to see if this OS can properly recognize the partition and access the data so that you can back it up. If that does not help as well, you could go for data recovery software:
http://www.tomshardware.co.uk/forum/id-1644496/lost-data-recovery.html & http://pcsupport.about.com/od/filerecovery/tp/free-file-recovery-programs.htm.
You can also try a partition repair tool, but I'd recommend that you go with the other suggestions first, as this might mess things up even more.
Please keep me posted on your progress.
Boogieman_WD