Ok guys i got a problem whit my Dension gateway 500. For the past week or two the unite keeps rebooting or losing connection whit the mmi. Some times the unite comes back by its self but some time i had to reboot the MMI. I was thinking off upgrading the firmware from 2.19 to 2.22 but i have the problem that it dose not recognize the usb. I try different usb and same problem. So can some body help me out her thanks. The car is a 2006 a6