Found the answer already
http://community.wdc.com/t5/My-Book-Live-Duo/WD-Red-on-My-Book-Live-Duo/td-p/434722
But really strange that WD doesn’t allow all of it’s drives in the same Size Range to be used in their systems !
Found the answer already
http://community.wdc.com/t5/My-Book-Live-Duo/WD-Red-on-My-Book-Live-Duo/td-p/434722
But really strange that WD doesn’t allow all of it’s drives in the same Size Range to be used in their systems !