为什么即使我释放大量内存以响应内存警告，iOS也会终止我的应用程序？

I can't figure out why iOS is terminating my app (iPad, iOS 4) due to memory usage even after I free a ton of memory in response to low-memory warnings. For example, here's a typical termination scenario, with me logging memory usage every so often -- look at the "app" usage, the first KB value on each line:I can't figure out why iOS is terminating my ap