http://blog.apparentsoft.com/business/124/is-paypal-good-for-your-microisv-business-a-short-paypal-horror-story/
I've had this same experience with paypal several years ago. They closed my account because they thought some transactions violated their terms of use. They would not tell me which specific transactions. They gave me conflicting information when i called them. And they also sat on the money in my account for 180 days before they let me withdraw it. Which is basically their way of forcing you into giving them a 180 day interest free loan.
I will never use them ever again for any online business. And i try to avoid using them for paying for anything online when ever i can. I refuse to link any bank account to them and if I wind up with any money in my paypal account i always spend it as soon as i can.
You might want to read this site as well before considering paypal: http://www.paypalsucks.com/
Paypal is not worth doing business with. The guys from the above post were lucky that they had a 2nd account to use. Otherwise they most likely would have lost ALL of their sales due entirely to paypal's unprofessional behavior.