sb5101 restarts when using a router

[pytyhon1564]

I read that thread and I dont understand why I would need to change my computer's MAC...
Also this is what my status page says:

HFC Parameters
Mode DHCP
IP Address 96.72.17.2
Subnet 255.255.240.0
TFTP Server 68.87.72.18
TFTP Filename d11_m_sb6120_walledgarden_c01.cm
ToD Server 68.87.72.18

Again another thing I dont get is why you dont want a walledgarden config. It worked for me for almost a year with walledgarden configs...