Hi Matthias,
What is the modified date of your oomph.min.js? It should be 9/30/2009 5:51AM
I would make sure your skin has the ScriptLoader control in layout.master, copy from one of the other skins in /Data/skins if not.
Also make sure you clear the browser cache.
If problem continues, is it a public url where I could look at it?
fyi, I just committed some other changes to trunk, but I'm pretty sure the oomph file was already updated previously.
Best,
Joe