title: How do you solve the iPhone error "signature is valid but not trusted"?
body: <p>Finally got MGTwitterEngine stuff to </p>
  
  <p><strong>compile</strong> (<em>by setting the Header Search Paths to /usr/include/libxml2  iphoneos3.0/usr/lib/libxml2</em>) </p>
  
  <p>AND <strong>link</strong> (<em>by removing the Twitter LibXML Parsers code and assigning a weak role to libxml2.2.dylib in Targets: Link Binary With Libraries</em>). </p>
  
  <p>But when I do a <strong>Build and Go to the iPhone</strong> (<em>not the simulator</em>), I get this error: </p>
  
  <p>"<em>This provisioning profile does not have a valid signature (or it has a valid, but untrusted signature).</em>" </p>
  
  <p>I have followed the official Apple Developer process of getting a certificate and provisioning, etc. Obviously, I did something wrong somewhere. Has anyone come across this problem or have any ideas on how to solve it?</p>