Dirk,
It is not clear from your post, if you have downloaded the plugin for version 3.02. If yes, please verify that the version 3.0.2 is compatible to Eclipse 3.4.2. In case this is a plugin, you can copy the plugin to MyEclipse installation dir/dropins/pliugins and features to MyEclipse installation dir/dropins/features and restart the IDE. If plugins and features folder are not already present in the dropins dir, please create the same.
Let me know how this works for you.
Best.