不确定这是什么... dns.so？ （我在iPod设备上只有这个问题......但模拟器工作正常。）
此警告（NSLog）显示在iPod上安装应用程序：
warning: Unable to read symbols for /Users/xxxxxx/Library/Developer/Xcode/iOS DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/info/dns.so (file not found).
warning: No copy of dns.so found locally, reading from memory on remote device. This may slow down the debug session.
此错误（NSLog）显示在iPod上运行的应用程序：
2012-01-09 18:32:12.071 PlotData[868:307] Received memory warning. Level=1
2012-01-09 18:32:18.256 PlotData[868:307] Received memory warning. Level=2
然后应用程序崩溃了...有时完全锁定iPod。