Scratch crashes when camera dialog box opened

To reproduce: Open Scratch. Click the costumes tab, click the camera button to open the camera dialog (which normally displays video from an attached webcam.) Scratch crashes with following error:

Executing: /usr/lib/squeak/4.4.7-2357/squeakvm -encoding UTF-8 -vm-display-x11 -plugins /usr/lib/scratch/plugins/:/usr/lib/squeak/4.4.7-2357/ -vm-sound-pulse /usr/share/scratch/Scratch.image

Recursive not understood error encountered

11059904 BitBlt>setDestForm:
11059688 BitBlt class>toForm:
11059596 WarpBlt class>toForm:
11059504 ScratchCameraDialog>step
11059412 Morph>stepAt:
11047524 [] in PasteUpMorph>runStepMethods
11046636 OrderedCollection>do:
11047248 [] in PasteUpMorph>runStepMethods
11046416 BlockContext>ifError:
11046300 PasteUpMorph>runStepMethods
10240896 PasteUpMorph>doOneCycleNow
10240804 PasteUpMorph>doOneCycle
4967164 [] in Project>spawnNewProcess
4967256 [] in BlockContext>newProcess

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: scratch 1.4.0.6~dfsg1-2~ubuntu12.04.1 [modified: usr/bin/scratch]
ProcVersionSignature: Ubuntu 3.2.0-27.43-generic 3.2.21
Uname: Linux 3.2.0-27-generic x86_64
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Wed Aug 8 19:06:48 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: scratch
UpgradeStatus: No upgrade log present (probably fresh install)