backup manager

hi guys,
I am trying to start Backup Manager from OEM.When I enter the user name, password and the service name (internal,oracle,service_name), connect as sysdba and click on ok, nothing happens.
All others like data manager, sschema manager etc. are running though.
What might be the problem?
I am connecting from an NT machine to the database on an Unix platform.
Thanks
manjunath

What is the OEm version you are currently using?

Thanks, Sam
OEM version is 1.6.0(Production)
manjunath