pitivi crashed with TypeError in setProjectFrameRate(): unsupported operand type(s) for /: 'int' and 'NoneType'

A crash in Ubuntu 14.10 on startup.

Similar to https://bugzilla.redhat.com/show_bug.cgi?id=1136327

ProblemType: Crash
DistroRelease: Ubuntu 14.10
Package: pitivi 0.93-4
ProcVersionSignature: Ubuntu 3.16.0-20.27-generic 3.16.3
Uname: Linux 3.16.0-20-generic x86_64
ApportVersion: 2.14.7-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Oct 6 08:30:49 2014
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/pitivi
InstallationDate: Installed on 2012-03-16 (933 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120316)
InterpreterPath: /usr/bin/python2.7
ProcCmdline: python2 /usr/bin/pitivi
PythonArgs: ['/usr/bin/pitivi']
SourcePackage: pitivi
Title: pitivi crashed with TypeError in setProjectFrameRate(): unsupported operand type(s) for /: 'int' and 'NoneType'
UpgradeStatus: Upgraded to utopic on 2013-10-23 (347 days ago)
UserGroups: adm audio autopilot cdrom dip libvirtd lp lpadmin motion plugdev sambashare sbuild sudo video