With usb connecting iPhone (iOS7), Xorg was frozen by clicking an iPhone icon on launcher.

Screen (maybe Xorg or compiz) was forzen and no windows were movable except mouse pointer, when clicking an iPhone icon on launcher, which appeared after usb connecting with iPhone (iOS7).
On the screen of iPhone, message dialogue to ask whether or not a user trust the connected PC poped up. Everytime "trust" is selected, the widnow disapears and popup again with the same question endlessly.
On the endless process, when the iPhone icon on Ubuntu was clicked then it was frozen.
In my environment, it is 100% reproducible. Note that iPhone (iOS6) and Ubuntu 12.04 work previously without any problems.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: usbmuxd 1.0.8-1ubuntu1
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
ApportVersion: 2.12.5-0ubuntu2
Architecture: amd64
Date: Tue Oct 15 16:37:43 2013
InstallationDate: Installed on 2013-09-21 (24 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130909)
MarkForUpload: True
SourcePackage: usbmuxd
UpgradeStatus: No upgrade log present (probably fresh install)