11gR2 clusterware downgrade failed

I failed to downgrade 11.2.0.3 to 11.1.0.7.

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run ./rootcrs.pl -downgrade -force -lastnode -oldcrshome /opt/app/11.2.0/grid/crs -version 11.1.0.7.0 on sso-ata10 failed with following,
Using configuration parameter file: /opt/app/11.2.0/grid/crs/install/crsconfig_params
Removing Clusterware entries in inittab
crsexcl failed to start
Failed to start the Clusterware. Last 20 lines of the alert log follow:
2012-08-03 14:20:09.931
[/opt/app/11.2.0/grid/bin/oraagent.bin(4457)]CRS-5016:Process "/opt/app/11.2.0/grid/bin/lsnrctl" spawned by agent "/opt/app/11.2.0/grid/bin/oraagent.bin" for action "check" failed: details at "(:CLSN00010:)" in "/opt/app/11.2.0/grid/log/sso-ata10/agent/crsd/oraagent_oracle/oraagent_oracle.log"
2012-08-03 14:20:09.973