device will connect others say no internet connection and connected devices drop

I just bought this router yesterday and the CM700 Modem, the modem works great! However, I'm about ready to have a fit with the router. I have 2 devices that will connect to the wireless router all other 8 devices keep getting a "no internet connection" message. Also the connected devices only 2 of them will just randomly drop connection and I have to log back into the wifi.. I need some serious help.. I have updated firmware and changed channels.. I have sent emails to costumer support but right after i push the send button it tells me that a fatal errror has occured. Not sure what the heck is going on..I've always used netgear products and this is the first time I've experienced this problem and I'm not having any luck with being able to get ahold of tech support.