Why does this format string turn "0" Blank?

[j0em0mma]

I have the following format string applied to a Report Column:

=Format(Fields!Units_Distributed_in_Date_Range.Value,"###,###,###")

For any value other than zero (actually zero, not a NULL value) this works, but a zero is displayed as blank.

If I change this line to this:

=Fields!Units_Distributed_in_Date_Range.Value

I get my 0's back, but then do not get commas on numbers of 1000 or greater.

What's going on?

Thanks in advance!

 

[j0em0mma]

SOLVED

=Format(Fields!Units_Distributed_in_Date_Range.Value,"###,###,##0")