A Study to Look at the Electrical Activity of the Heart in Subjects With Solid Tumor Cancers, Before and After Receiving the Study Treatment, GSK1120212

GSK1120212 - placebo match oral dose on day 1 with GSK1120212 3 mg oral dose on day 15. GSK1120212 2mg and 2 tablets of GSK1120212 -placebo matched 0.5 mg oral dose daily from day 2 to day 14. 24 hour holter monitoring will be performed on day 1 and day 15 to compare the subjects cardiac repolarization while on placebo and after having received GSK1120212 for 14 days