Can i have 2 My Passport Elite connected at the same time?

Hello all.

I have a wd My Passport Elite 640gb and yesterday i bought a new one. Its the same but with usb-dock.

My first wd drive its set-upd correctly and shown in “My Computer”

But, when i plug-in the new one, i only see 2 (two)  “CD Drive (I:) WD SmartWare” and “CD Drive (G:) WD SmartWare”

and 1 (one) My Passport.

At “Disk Management” i can see both of them, but one offline and i get a message that says : 

“Offline (the disk is offline because it has a signature collision with another disk tha is online”

Keep in mind that i have already change the names of the disks.

My system is Windows 7 (64bit)

Any ideas of what is wrong or any tip ?

Thanks.

Edit : i found the solution from this post —>

http://community.wdc.com/t5/My-Passport-for-PC/can-you-connect-2-passports-at-the-same-time/m-p/49636#M2109