Hi ergggo,
I'm not sure if this is the exact problem you're having, but a similar question was posed in an older thread, and the developer replied with this:
This is a common place for people to get stuck, and ironically enough it's the walkthrough's fault. Go back to Rosa's apartment and talk to Joey again. Make sure to ask him about his "special powers." Once you find out what his powers are, then you can get him to blow on the papers.