SchulieBug, What you need to do is disable the usbarbitrator service and then try it again. The command to do so is  /etc/init.d/usbarbitrator stop Let me know how it goes.
We got 4 R710's with all VMware ESX 4.1.0 on it. We patches those servers this week with the latest VMware patches and one server wasn't able to reconnect to the vCenter cluster. We then did a reïnstall with the latest VMware ESX 4.1.0 ISO (Update 2), installed all the VMware patches and no problem. Installing Dell OpenManage 6.5.0 (also tested with 6.3.0) and after reboot the server couldn't reconnect to the vCenter cluster. Anybody an idea?
R710 with VMware ESX 4.1.0 Update 2 error connecting from vCenter after latest 
VMware patches