The study is expected to identify a safe dose of BMS-754807 to be given in combination with a standard dose of cetuximab and the recommended dose or dose range for Phase II studies. The study is also intended to collect first data on the effects of the combination of BMS-754807 with cetuximab on tumors of patients with colorectal cancer or squamous cell cancer of the head and neck for whom cetuximab-containing therapies have not been effective