My problem was that I have a PayPal business debit that links to my paypal balance the same way a bank debit links to your checking account. I was using it to purchase coins using coinbase's instant purchase. 3 transactions in 24 hours was enough for PayPal's system to flag the card as potential fraudulent purchases and lock me out.
So I had the pleasure of spending over an hour and half on hold with paypal to get a hold of a representative. They were able to unlock the account, but told me if I made more than 2 or 3 purchases in a day, it would lock me out again. So guess I need to make fewer, but larger purchases
It's dodgy, should be able to make as many as you want...its your money!