MobileSync Protocol can't clear all contact on iphone
<p>I use the <a href="http://www.libimobiledevice.org/docs/mobilesync.html" rel="nofollow">MobileSync Protocol</a> to handle my contacts on my iphone. </p>

<p>First, I use <strong>AMDeviceStartService</strong> to start com.apple.mobilesync service and get the socket ok.</p>

<p>Second, I send <em>SDMessageGetAllRecordsFromDevice</em> to get all 
and succeeded. </p>

<p>Then, I send <em>SDMessageClearAllRecordsOnDevice</em> and received <em>SDMessageDeviceWillClearAllRecords</em>, but nothing happend on my iDevice's contacts!</p>

<p>Can some one known the reason? Thank your very much.</p>

<p>PS: I test on Mac 10.7, with Xcode 4.3.2</p>
