Ok so to start of, my first time in Brazil was May 10th 2009 (this will be important later). I stayed for 2 months in Belo Horizonte and then returned back to the USA. The next time I came to brazil was Aug 2011, for 20 days. Then I came back again January 11th 2012. Now I stayed my 90 days until Apr. 10th, and then went to get my extension with the PF. However they did not give me 90 more days but rather gave me until May 10th, only an additional 30 days. I told them there must be a mistake because even with my previous visit I should have received 62 days. The officer then proceded to tell me that the 1 year period starts from the very first time I came in brazil (May 10th 2009) and will always be that date. So that no matter if I have used my 180 days I need to leave the country every may 10th. However he then advised me just to go to argentina for a couple days then I could come back after may 10th and receive 180 fresh new days!
So essentially this means that if you plan things right, you can stay in brazil for a full year, with a short trip in the middle. I am still here and am only going back in november because I need to use my return flight within a year of buying it haha. Any questions about this let me know!