As the PTO you are the closest thing some people feel they have as a sounding board for questions, comments, or ideas. As a result people tend to think you have a hand in things that you don't.
Whenever people come to us about something that has nothing to do with us, we simply tell them that the issue has nothing to do with the PTO and direct them to whom they really need to speak to.
I really do not see any harm in this and it only takes a second to inform someone that it is not PTO related and to redirect them. You can tell people to only speak about PTO related issues, but really only die hard members will know what things concern you and what things do not.
Incidentally, many PTO's are running coin drives for the Tsunami victims. Our school is just one of them. It has been a great lesson for many of the children about helping others.
We have been having problems at our PTO meetings with members bringing up issues that aren't really related to the PTO. For example, a member wanted to sell items to raise funds for the tsunami victims. Our goal as the PTO is to support the school and the students. We are deeply concerned for the victims but that is an issue that should be addressed by the principal. There have been other issues also. How can I politely request that only PTO issues be addressed?