Unable to combine commandblock spawned items with hand spawned items

I am trying to build a password sensitive piston door. For this password you have to drop a paper named ''Code: 5051" into a chest. This chest contains 123 papers named "Code: 5051." With the 124th I'm able to get a redstone signal of 2 redstone dust in length. This length is enough to open the door. Problem is, those 123 papers in the chest are spawned by hand. The 124th paper is spawned into a dropper with the help of a commandblock. For some odd reason I am not able to stack the 124th paper with the other papers. (Note: the 123 papers are spawned with /give, the 124th is spawned with /setblock).