Let me caveat by saying I'm not really familiar with Netgear routers. However, all personal wireless routers have similar features. It's just a matter of where to find them.
First, I'm going to assume when you say "router site", you're talking about the web-based configuration page for the router and can therefore access the router config. MAC Filtering should be somewhere under the Wireless section, either directly or possibly under a Wireless Security sub-menu. (If you can't find it, look up the features for your model on the Netgear web site to see if MAC filtering is supported and where to find it.) Make sure that it's turned off for now while you're troubleshooting (or at least that your mac address is listed and that it's set to allow or permit if you can't disable it)
As to the 802.11 setting, that can be found in the Properties dialog box of your wireless network connection. Click on the Configure button at the top of the General tab and then go to the Advanced tab. Which property this is under will depend on the model of your wireless adapter, but it may be under IBSS Mode or some other Mode setting. Just scroll through the list until you see something in the value box that looks like 802.11a/b/g/n. While you're in there, you can check the channel number. I'd also recommend disabling any acceleration features (Afterburner, etc.) and setting anything that lets you choose between compatibility or performance to compatibility.
Can you provide more info about the OS you're running and the model of your Netgear router.
