Brief report:
Our 1st attempt on Cotopaxi was on January 5, 2006. DeeDee and I woke up at 12:15am. We started to climb at 1:30am. Socked in clouds; poor visibility; 1.5 feet of new snow overnight meant avalanche risk. We decided to turn around at 5255 meters (17,241 feet) at 4:04am. Back at the Jose Ribas hut at 4:56am. Went to sleep from 5:00am 'til 9:00am. Defeated by conditions, we went down to Hosteria La Estacion to rest overnight.
Our 2nd attempt on Cotopaxi was on January 7, 2006. Woke up at midnight. Started climbing exactly at 1:00am. Got to the ice wall near the Yanasacha before dawn. Waited for daylight to tackle the crux of the route (a small 50 degree step) by the bergshrund. Summited at 7:40am. Stayed 15 minutes at Cotopaxi's summit. Back at the hut by 9:53am (~ 9 hrs roundtrip). Then, we drove down to Aloasi for much-needed rest at Hosteria La Estacion.
Additional info about climbing Cotopaxi can be found here.