Why is Clearcase install failing?

I am getting below error while installing Clearcase through installation manager. This is the command I ran:

./../IM_lnx_1.5/installc input /tmp/temp_response_file -acceptLicense -svp

It fails with below error:

/IM_lnx_1.5//jre_6.0.0.sr9_20110208_03/jre/bin/java -Xquickstart -Xgcpolicy:gencon -jar /IM_lnx_1.5/plugins/org.eclipse.equinox.launcher_1.1.1.R36x_v20101122_1400.jar -os linux -ws gtk -arch x86 -launcher /IM_lnx_1.5/installc -name Installc --launcher.library /net/jer-lvob-/IM_lnx_1.5/plugins/org.eclipse.equinox.launcher.gtk.linux.x86_1.1.0.v20100503/eclipse_1307.so -startup /IM_lnx_1.5/plugins/org.eclipse.equinox.launcher_1.1.1.R36x_v20101122_1400.jar -exitdata 508006 -toolId installc -accessRights admin -silent input @osgi.install.area/install.xml input /tmp/temp_response_file -acceptLicense -svp -vm /IM_lnx_1.5//jre_6.0.0.sr9_20110208_03/jre/bin/java -vmargs -Xquickstart -Xgcpolicy:gencon -jar /IM_lnx_1.5/plugins/org.eclipse.equinox.launcher_1.1.1.R36x_v20101122_1400.jar

00:26.08 ERROR [main] com.ibm.cic.agent.internal.application.HeadlessApplication runAgentNoStdout
java.lang.NullPointerException
java.lang.NullPointerException
at com.ibm.cic.common.core.preferences.CicPreferenceManager.removeBackup(CicPreferenceManager.java:479)
at com.ibm.cic.agent.core.Agent.stop(Agent.java:524)
at com.ibm.cic.agent.internal.application.HeadlessApplication.run(HeadlessApplication.java:546)
at com.ibm.cic.agent.internal.application.HeadlessApplication.run(HeadlessApplication.java:409)
...
00:26.08 ERROR [main] com.ibm.cic.agent.internal.application.HeadlessApplication run
java.lang.NullPointerException
java.lang.NullPointerException
at com.ibm.cic.common.core.preferences.CicPreferenceManager.removeBackup(CicPreferenceManager.java:479)
at com.ibm.cic.agent.core.Agent.stop(Agent.java:524)
at com.ibm.cic.agent.internal.application.HeadlessApplication.run(HeadlessApplication.java:546)
at com.ibm.cic.agent.internal.application.HeadlessApplication.run(HeadlessApplication.java:409)

quick help will be appreciated.

Thanks
Vineet