Crosstab totals incorrect

[Guest]

I have a crosstab query with two row headings, four columns, and one totals
column where the average is calculated for each row. If one of the columns is
missing a value for one of the rows, the value in the totals column is
incorrect for that row. It is neither the average of the three columns that
have values (which is what I want), nor is it treating the missing value as
zero. It is some other value.

Why is this and how do I make it calculate the average correctly?

 

[Guest]

Never mind. There was the equivalent of a duplicated record in the source db,
so one of the values was averaged in twice. It was a coincidence that this
happened in the row with the missing value (actually not, one of the records
is probably mislabelled).