我的iphone4綠毒4.2.1今天發現無法下載及更新app，它顯示
You've already purchased this but it hasn't been download.if you've having trouble downloading it,select check for available downloads from iTunes on your comPuter,then sync with your device.，
但我接上傳輸線使用iTunes同步備份也還是不行！
請問我該怎麼辦？難道只能回復嗎？我不想被強迫更新為4.3.1啦～ （−＿−；）
