Ever since I jailbroke my iphone 4 I get the following error when I try to update my paid apps through the app store on my phone. "This discounted price is only available to customers who own a previous version of this item. To purchase this item at full price, click Buy. You have not owned a previous major version of this software. You have to buy it at full price. Would you like to buy it? Then when I click on buy it I get the following error "This item is currently being modified. Please try again later." Any suggestions on how to fix this problem? It was having no problems before I jailbroke my phone.