We had a similar problem a few years back when the outgoing president took the last 10 years worth of files with her when she left. She did it because she wanted the new board to fail, which is sad because if the board fails the ones who truly suffer are the children and that is what we are in this business for!
The one thing that is so wrong when people behave like this is that the supplies, files, and whatever else is taken belong to the organization and not to individual people. If they bought the supplies with PTO money then those supplies belong to the PTO and what they have actually done is stolen items.
Clearly they are mad about something and maybe finding out what it is will help, but regardless of what they are angry about their behavior is terrible.
Have you spoken with the prinicpal? Is it possible he/she could speak with them and get to the root of the problem and ask them to return what they took? If not the principal, is there another person who is friendly with you and them who can at least try to get to the bottom of what the problem is?
Worse case scenerio....if nothing gets accomplished or returned then you and the current board will have to do you best to try and cover all your bases. You can consult with people who have chaired events in the past and past board members to try to cover all your bases. That is what we had to do and in the end we managed just fine and created a whole new set of files and had an awesome year.
Lastly, because this happend to us, we changed our bylaws to make sure they stipulate that board members cannot take things that belong to the organization. Out going board members have 1 month after they leave office to return any files or materials they have that belong to the organization.
This sounds like my first year as co-president several years ago. the board that was in place before us left us with nothing (including no money) They said this was the way they came in, so why should they be different. If you have to start from zero, then get the best people you can around you and GO FOR IT!! It is for the kids and the school, and if they want to be petty I guess there's nothing you can do. Have a great year and show them you didn't really need their help.
This is my 1st year in the PTO and the outing borad members (VP) will not help me at all. They took everything inculding all the supplies out of our PTO storage unit, wont return my calls to answer any questions and are just rude! What do I do with members that are being nasty becasue they had a bad year? One of them I thought was my freind, but she wont even return my calls. I thought we were all in the PTO to help our kids not to be like this!