Upgrade was succesful, but strange admin interface

I have upgraded 2.6 to 2.7 and all is working fine. But most of the time when I click on edit post I get the add media block(Media
To attach media to this entry, either use the file uploader below or drop files into the following folder using ftp software:
[WordPressFolder]/media/2009/01/07//

Enter a file to add new media (this can take a while if the file is large):) on top of the standard WordPress 2.7 lay-out. How can I fix that?