jclic's windows never wants to close

[Micouin Claude]

Pardon for my bad english.
Jclic works normally, but it's always impossible to close its windows (except with xkill). It occurs with Ubuntu 14.04, but it was the same with the previous versions too. I've let the messages of errors written in the console in the file jclic_console_errors.txt
I hope I didn't forget nothing. Thanks.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: openjdk-7-jre-headless 7u55-2.4.7-1ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CurrentDesktop: Unity
Date: Tue May 13 23:34:33 2014
ExecutablePath: /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
InstallationDate: Installed on 2014-05-07 (6 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: openjdk-7
UpgradeStatus: No upgrade log present (probably fresh install)