First part- We want to learn more about the best dose of vorinostat to be given with lapatinib. We want to learn about how much vorinostat and lapatinib goes into the blood during treatment. We also want to learn the side effects (safety) of the combination of vorinostat and lapatinib. All patients will receive the FDA-approved dose of lapatinib. The first group of patients will get a slightly lower dose of vorinostat than is given normally. If the side effects are not too serious, the next group of patients will get the dose of vorinostat that is given normally.