I posted this in General Questions but didnt get a satisfactory answer.

I have a workbook that is used for estimating and manufacturing process
control and has been used for many years. My problems have occurred since I
tried to migrate to Excel 2007. I opened the workbook in 2007 and saved it as
an .xls file compatible with older versions. The size of the file increased
from 3.0mb to 3.6mb. It has numerous formula errors.

I have deleted all data and code except for 2 of the many cells with formula
errors. I have saved this as a workbook. It is now has 516k with only 2 cells
populated. I would like someone to look at this and give me some advice on
what to do. Is this increase of 500K normal? Is this a Microsoft problem?