Here are the steps to recreate this issue:
1) Create a keystore using keytool.exe available in JAVA_HOME/bin.
2) Now use the command "deploy unlockKeystore <Keystore_Name>"
An exception is thrown suggesting "keystore does not exist".
To overcome this exception access the admin console keystore portlet, this operation will add the newly created keystore as a gbean into geronimo.
Now try #2 unlock will be successful.
To fix this issue up there are 2 possibilities on which I will put up a discussion on dev list.