First serious run questions.

[skoooter]

I just got through with my first BW run. Fermentation went well, it got to .0990. Using a column still I raised the temperature very slowly and started getting distillate around 72. Tool the first 250ml and tossed. Temp still at 73-74. Began collecting and went pretty smoothly I thought. Collected only about 2.5 liters, to be safe. After i got through I started checking and found that the first 750 ml were only 75% alcohol, the second 750 was 60% and the third was only around 55%. I kept the temperature around 74-81. Occasionally the condensor would seem to "flush" and large amounts of distillate would come out at once. Any help would be greatly appreciated.