Comment 5 for bug 1082877

Hmm, well, I found the problem and also could 'fix' it:

I connected my smartphone (Sony Neo V) to the Notebook to use USB tethering. I don't know what I did, maybe I disconnected the smartphone without deactivating thethering. But this gave me the issue.
I just connected my smartphone again for battery charging, and due to the issue it wasn't found by Ubuntu. But while it was charging, I just played with the thethering options - and suddenly, Ubuntu detected my smartphone. Then I tried to connect other USB device - all devices are working with hotplug now.

So, this was definetly the error. I tried, but I couldn't reproduce the issue.

Anyway, I think it is still a bug. I attached the relevant part of the 'syslog', whereat there are no special informations. There were no messages in dmesg.