I searched a long time but it seems that no one else got the problem I have.
After I downloaded a clean version von eclipse 3.1.2 I installed GEF 3.1.1, EMF/SDO/XSD 2.1.0 and JEM 184.108.40.206. After that I used the Installation Guide from the Spring Homepage. That means setting up the Eclipse Update Manager.
After everything works out fine. I got the logo in help -> about eclipse and every Plugin is loaded (checked under help -> software updates -> manage configuration).
But I can not create an Spring Project. The only thing that works is the Spring View and the menuentry 'Add spring project nature'. But nothing else. The spring View does not show anything except of the project itself.
I tried Eclipse 3.1.1 also. I have no clou why this do not work.
Thanks for any help,