Here's the situation: In Touchdown (Exchange Email app) I click on a PDF attachment icon. A message is displayed stating that the PDF file is being downloaded but the PDF file never opens. Here's what I think is wrong: I have downloaded Documents to Go, free version. It will display PDFs, but not in the free version. I'm thinking that Documents To Go became my default PDF reader but since the free version won't show PDFs it just does nothing. How do I determine which application is the default for PDFs? Once I determine that, how do I change the default back to the application that comes with the Droid? This all worked fine before Documents To Go was installed. Any help will be appreciated.