Darius Q stack transfer is inconsistent

http://media-copper.cursecdn.com/attachments/29/180/darius_q.jpg

I'm a Darius main and one thing I like to do is transfer 5 stacks of bleeding to multiple enemies from one Q on an enemy with 4 stacks. i've tested this and it does not always work. I am also always hitting with the blade because all enemy will have at least one stack after I Q all of them. Please fix this as the outplays are there.