Source ID was not found when attempting to remove it

Heaps of warning messages to stderr when viewing files:

/usr/lib/pymodules/python2.7/mirage.py:3827: Warning: Source ID 3105 was not found when attempting to remove it
  gobject.source_remove(self.load_when_idle)
/usr/lib/pymodules/python2.7/mirage.py:3831: Warning: Source ID 3109 was not found when attempting to remove it
  gobject.source_remove(self.preload_when_idle)
/usr/lib/pymodules/python2.7/mirage.py:3835: Warning: Source ID 3110 was not found when attempting to remove it
  gobject.source_remove(self.preload_when_idle2)

Don't know if it's a problem with GTK+ or a problem with how GTK+ is used.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: mirage 0.9.5.1-1.1
ProcVersionSignature: Ubuntu 3.13.0-36.63-generic 3.13.11.6
Uname: Linux 3.13.0-36-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.4
Architecture: i386
CurrentDesktop: XFCE
Date: Sat Oct 11 22:44:07 2014
InstallationDate: Installed on 2013-06-08 (490 days ago)
InstallationMedia: Xubuntu 13.04 "Raring Ringtail" - Release i386 (20130423.1)
SourcePackage: mirage
UpgradeStatus: Upgraded to trusty on 2014-04-20 (174 days ago)