I have upgraded from postgresql 8.4.4 to 9.0.1 and restored the backed up databases.
Than I have imported the customers solution, but now all the medias in the solution are gone!!? The medias are existing in the developer from I exported the solution.
The media is not gone. You need to use the latest PostgreSQL jdbc driver.
You can download it from http://jdbc.postgresql.org
Make sure you remove the old driver from the drivers directory.