Everyone calm down.
The issue here is a chemical reaction between specific flavoring agents to a specific plastic - polycarbonate. This link has an interesting explanation of the process:
» Why Do Some E-liquids Crack Plastic Tanks?
The molecules of certain flavors can have a chemical attraction to certain components of polycarbonate plastic. As more and more bonds are made, the plastic weakens and either cracks or melts. This in no way means that these specific flavors do the same thing to your lungs when you vape it.
As an anology, everyone here likely drinks soda pop and has had no issues with it dissolving away your stomach. But many people will apply soda pop to the corrosive buildup on a car battery's terminals to make it dissolve away.
The choice is obviously your own to decide whether to vape one of these flavors. I have a few Cinnamon and Citrus Flavors that I have used for months and have had no pulmonary problems from doing so. Nearly all of my juice delivery devices are made of pyrex glass.
For additional information on this topic, including a video of a clearomizer melting and safe options to use with these flavors, read this blog article that I wrote:
http://www.e-cigarette-forum.com/fo...6-something-safe-cinnamon-citrus-flavors.html