yes unfortunately i've had this same thing happen and it is never pleasant. Paypal will ask for you to send them some documentation when they do this. depending on what the reason was, they'll ask for your ID, ssn, confirmation of your contact info, business certificate, suppliers info (if you was selling a physical item.) After you send them that they will review the info and that can take 90 days and in some cases up to 120 days. I know some people will suggest you call but I and many of my colleges have been through this and in the vast majority of instances the only thing they tell you is to send them the info they've requested and wait. So, that is really all you can do.
Paypal will also limit your account if you visit a phishing site. This happened to me. I received an obviously fake "paypal" email, and was curious to check out the site it was hosted at. The phishing site was a copy of the paypal site, and used the images directly from paypal. I guess they tracked the ip's that loaded the images from the phishing site and limited their accounts, just incase they had submitted their login info.