[Mondrian] question about rounding

[John V. Sichi]

The following query returns 0, whereas if the quotient is 51/100, it 
returns 1.

with member [Measures].x as '50/100', format_string = '0'
select {[Measures].x} on rows
from sales;

Is there a reason it matches BigDecimal.ROUND_HALF_DOWN instead of the 
much more common BigDecimal.ROUND_HALF_UP?  Is 
BigDecimal.ROUND_HALF_DOWN required by the Visual Basic format string 
standard?

JVS