I have a 1284p-based board (of the Mighty1284 design) with a Wiz820io (W5200) module. Everything seems to work with the Ethernet52-library (https://bitbucket.org/homehack/ethernet52/src) except the watchdog.
As soon as my sketch has an instance of EthernetClient, the watchdog simply crashes the system and the program is never successfully rebooted.
Anyone have insight into this? I am a bit confused that a library is able to make such an impact.
EDIT: I found that having an instance of EthernetUdp does not interfere with the watchdog. EthernetClient and DNSClient does, however.