OK, i fixed the problem and maybe it is useful for someone... After reading that many people facing problems with groundloops, i discovered that my Notebook-power supply causing the issues. I disconnected the Notebook power supply and holding down the nav rigth on powering up the POD. With Line6monkey i done a normal FW update and it worked. After powercycling the POD there "sons of Plexi" coming up in LCD. Maybe it is helpful to place the POD on a electrical non-conducting surface and pull everything from the POD but the USB. If your PC/Notebook is the problem it can also be helpful to pull at least all additional USB-Connections and in case of using a Notebook to pull the power-supply. Now i`m going to test the new firmware... :-) Greats from germany