SDK no Eclipse - Linux Ubuntu

Bom Galera preciso instalar o Android SDK aqui no Ubuntu, ja instalei no Pc , e configurei uma AVD mas na hora de configurar no Eclipse (Ajuda - Instalar Novo Software - ADD - e colocar em URL [https://dl-ssl.google.com/android/eclipse/] - e selecionar Developer Tools da esse erro /

{Your original request has been modified.
“Android DDMS” will be ignored because it is already installed.
Cannot complete the install because one or more required items could not be found.
Software being installed: Android Development Tools 20.0.1.v201207132230-403220 (com.android.ide.eclipse.adt.feature.group 20.0.1.v201207132230-403220)
Missing requirement: Android Development Tools 20.0.1.v201207132230-403220 (com.android.ide.eclipse.adt.feature.group 20.0.1.v201207132230-403220) requires ‘org.eclipse.wst.sse.core 0.0.0’ but it could not be found}

Alguém ja passou por isso antes ?!? como resolver ?

Obrigado !