my polaroid and me... part 2

A couple of posts ago I was whining about how my polaroid decided to put ugly brown stains on each photograph. So yesterday I gave it another shot :) and took two more pictures. 

As I predicted: huuuge brown stain

The second one..

No stain? What's happening?

 I do not have the slightest idea why the second photo is stain-free. I guess my polaroid just does what it wants. We'll see how the last photo will turn out...