I have Microsoft Powerpoint 2010,

Sometimes when I read or download ppt files of people who have older versions of office, and I make changes to the file and want to save them, it always warns me about checking compatibility etc, I check off the little box so its unchecked and click so that it doesn't ask again and click save, but for different files it asks again, how can I get power point to stop checking all together? what consequences would that have? Thanks