The firefox extension, Ad Block Plus, caused trouble in the presentations application. I also noticed that, in the my files application, while scrolling down a pdf document using the scroll wheel on my mouse, document to jump back to the top after viewing a couple of pages.
It is probably a good idea to disable ad block plus on all acrobat.com applications. You can do this by clicking on the ABP icon in firefox and choosing "Disable on ..." for each of the applications after you've logged in. You'll need to reload the page.