Google decides to just change the way they calculate active installs and everyone's 30 day chart drops like a rock because they then compare these calculations with the old calculations.
Who is in charge of quality control in this Android Market? Developers are going to revolt if Google keeps this up. There doesn't seem to be any real concern for developers marketing efforts and no real attention to details. I wonder why.
UPDATE! Google has resolved this 30 day chart issue. Good job Google!