I have been having a similar issue. I tried updating my firmware on my 'My book 1 TB' hard disk. I got some message which said that the firmware update did not go through correctly. (I wish I had the screen shots - but I don't) and I don't remember the message verbatim.
Anyway, I thought retrying would help, and it hasn't. There are two issues here,
1) When I connect my hard disk to the computer (running Win 7 home premium), the virtual CD is recognized, and assigned a drive letter. I have the drive locked.
2) When I unlock the drive, it says 'unlocked', but I don't see my data partition.
3) When I try reinstalling the driver, it just keeps running, and windows tells me from time to time that the process is hung.
I am not sure what I am supposed to be doing here. I mailed WD and all I get it a link to this forum, like that's going to help!! I wouldn't mind sending in my drive to them, but I am not even sure what data I have on it and will lose.
If someone could help me out here, it would be great.