I started a draftsight drawing consisting of a map that covers a 4,000' x 4,000' area. I started the drawing using the Decimal Unit System. But after about 10 hrs of drawing I decided to go to Architectural Unit System. My Block Units Format is still set to Feet. Now the dimensions are messed up. Where a distance measured 7' it now measures 7". A distance measuring 104' now measures 9'-4". If i switch back to Decimal Unit System everything goes back to normal. What is the problem?