Waiting for Paypal

Normally I don't sell to those with no feedback on Audiogon or eBay, but occasionally I make an exception. Once the paypal account shows that I have the money from the buyer, I request a check immediately. Is there a safe length of time to wait before I ship the item? Is it safe to ship once I receive the check from Paypal? My bank account is linked to Paypal. If there is a default later on, can Paypal pull the money back out of the bank account even if they sent me a check in the mail instead of direct deposit? What would you do? Thanks.