borbelyimi
Before I uninstalled the Java3D the version in the about dialog is 1.6.0.
After I uninstalled Java3D 1.5.1 the version in the about dialog is the same (1.6.0).

same for me with 64 bit mode extremely slow and installing and uninstalling did not change anything (only Webstart 32 bit worked)

borbelyimi
Then I installed the Intel graphic driver and the 3d view is good! I think the Java3D is unnecessary, but I didn't uninstall it.

This finally did the trick! After updating the Intel Graphics Driver, I can work in normal desktop mode with 64 bit again! Looks like the Intel Graphics Driver could not work with Java 3D 1.6 in 64 bit mode.

Thanks borbelyimi for finding this solution!