I. To define maximum tolerated dose (MTD) and the dose-limiting toxicities (DLT) of MK-2206 (Akt inhibitor MK2206) in combination with trastuzumab and lapatinib (lapatinib ditosylate) in adult patients with locally advanced or metastatic HER2-positive breast or gastric cancer; two schedules of lapatinib administration will be examined-continuous daily dosing and pulsatile dosing.