Key gets double tapped when changing workspace under gnome3

steps to reproduce:
- open gnome-shell and onboard
- place 2 teminals on 2 workspaces
- change the workspace, focus a terminal and hit a key

when I type 'cd' I see 'ccd'.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: onboard 0.99.0~alpha1~tr1190-0ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-8.17-generic 3.8.0
Uname: Linux 3.8.0-8-generic i686
ApportVersion: 2.9-0ubuntu2
Architecture: i386
Date: Sat Mar 2 11:41:42 2013
InstallationDate: Installed on 2013-02-08 (21 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release i386 (20121017.2)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: onboard
UpgradeStatus: No upgrade log present (probably fresh install)