this can be for various number of paypals policy regarding your account. if you sell stuff and not receive the money as family member things such below written creates the hold up.
• You have been an eBay and PayPal member for less than 6 months
• You have an eBay feedback score of less than 100 and do not have a record of good performance
• You have a Buyer dissatisfaction percentage of 5% or greater
• You have an average Detailed Seller Rating (DSR) of less than 4.5
• You have received fewer than 20 Detailed Seller Ratings in the last 12 months
• You have a high rate of customer disputes
• You’re selling in a high risk category or industry such as, tickets, travel, gift certificates, computers, consumer electronics or mobile phones
For instance this is what is says on withhold payments:
Payments you receive go to your pending balance. Payments in your pending balance belong to you, but you can't use them or withdraw them. After you have a successful selling history with us, payments you receive go directly into your available balance shortly after they're sent, as long as your customer hasn't reported any problems with the purchase.