Ouch!
Yes, my bad… when I updated to the RC, I enabled debugging in the config file... I've disabled it now.
Thanks a lot!
If you were getting those aux:M408 reports from Pronterface, then a M111 S1 command has been executed at some point to turn debugging on. That could be responsible for the network issues too. Next time you get these issues, try sending M111 from PanelDue to report the current debug state. If any debugging is turned on, send M111 S0 to turn it back off.