I built a new home in michigan . I am having a major problem with ice forming on in the center of my windows and inadequate heating to several rooms. All of them are doing it.

The following things have been done to eliminate the problem but have not worked:
1. Blew more insulation in the attic.
2. Cleaned the windows to make sure they close tightly.
3. Checked the furnace and duct work - air flow, negative pressure, and etc..
4. Checked for high or more than average humidity.- No problem found
5. Changed the Furnace Filter.

Several rooms at times are 7-10 degrees lower than what my thermostat is set to.

Note: During the month of December 2005, my thermostat was set to 78 degrees and still several rooms did not get over 71 degrees.

The builder and window manufacturer said the windows are manufactured and installed properly.

What do you think? thanks for your help we are freezing!!!.