Hey guys. I know this is quite an old topic, but I'm facing the same problem as OP.
I am using ACT Corp Fibernet. On WAN Port rate 10/100 Mbps or 100 Mbps, my router doesn't get an IP Address from my ISP's DHCP server. But, when I change the WAN Port rate to 10 Mbps, it works fine.
What is causing this problem?? How can I fix this.
I know this product support is over, but this product is still sold everywhere in India :/