IPI-504 is a novel small molecule inhibitor of heat shock protein 90 (Hsp90), an emerging and recently identified target for cancer therapy. Hsp90 is a protein chaperone that plays a central role in maintaining the proper folding, function and viability of various "client proteins". Many of the client proteins stabilized by Hsp90 are oncoproteins and cell-signaling proteins important in cancer cell proliferation and cancer cell survival. This clinical trial will study the effects of IPI-504 in a molecularly defined sub-group of patients who carry client proteins found in non-small cell lung cancer.