Linksys Wireless Router :: E2000 Will Not Load Certain Websites Through CM100?

Short version: when running devices through my e2000 into my CM100 modem, internet access is unstable, packets are lost, and certain websites simply will not load. I am using my apartment complex's **bleep** internet (and I have no choice in the matter) which registered the MAC address of the CM 100. When I run through the CM100 directly, everything works fine. What can I do to fix this?
 
Long version: I have an e2000 router connected to my PC, Xbox, and wireless devices. The router is then connected to a CM100 cable modem. The modem is connected to my apartment complex's internet access. They required the MAC address of the cable modem. The routed showed an apartment complex domain when I went hunting around, but there is no login to it, and I was never told anything else about the connection.
 
When I run the router through the modem, the internet access is lousy. Certain websites will never load, the connection drops, and packets are lost. When I run directly through the modem, the connection works perfectly.
 
I note that the CM100 assigns IP addresses if it cannot get any from the ISP, and there appears to be no way to turn it off. I have tried disabling DHCP on the router, but it did not work. I have changed the router's IP address, but that did not work. I have even tried turnign the router into a simple wireless access point, but that did not work. The modem is at 192.168.100.1, while the router is on 192.168.1.1. Should I change my router's location to 192.168.100.x?