I was testing Vijay's solution: switsching motherboard USB from High speed to Full speed and it works now without problem. Comment from Asus: EHCI hand-off support is missing.
What's EHCI? Is it finally a bug or not? Thanks for your precious help. -- After upgrading from breezy, the system will not boot https://launchpad.net/bugs/77922 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
