I am not sure why this particular pane of Google's keep changing !!!

I am used to this pane where I click on the drop down button and the 'Reader' is first.

Sometimes, 'Documents' and 'Reader' is interchanged and I end up opening Documents instead of Reader, obviously because I am used to clicking the drop down where the first item on the list is Reader. (I don't have a screen shot now though !!! ) Aaaah....I am used to this interface. Google...please don't keep switching the positions of the items. Seriously, it's confusing and yeah....annoying !!!