TheRealReal:
I have the Asus RT-N56U (running Padavan firmware) and a MyCloud 2TB. Works fine though I’ve only had it a week or so. I have UPnP enabled on the router, no port forwarding. I wonder why you need to use port forwarding for your MyCloud? How are you trying to access your MyCloud? Through a computer on your home network? From outside your home network? By the way, I use my MyCloud as a NAS and to stream video content to two WDTV Live devices in the house. I have not tried to utilize its “cloud” functions yet.
Update: I activated a cloud account and downloaded wd2go to my iphone. Access to my MyCloud works perfectly. Nice app… I will also add that my MyCloud updated to the latest WD firmware this morning.
I recommend updating the FW and enabling UPnP on your Asus router. You might also try the Padavan FW for the N56U.