The computer problem that arose yesterday was resolved (the video card had gone bad) in Tucson and the unit was brought back to the mountain during the day as drier air moved into southeast Arizona. The change in air flow resulted in very workable and productive night. It was generally clear, but not often photometric. Light cirrus welled up from the south for most of the night. Only very rarely was polarimetry slowed by thicker patches of cirrus. The seeing was usually between 1-1.5 arcsec.