I have a report with a field that uses a variable with a numeric datatype as it's "Expression"

SUM Cost ALL FOR Distr TO m.nTotalDistrCost
m.nTotalDistrCost = ROUND(m.nTotalDistrCost,2)

When I run the report (set enginebehavior = 80) and I have the format set as Numeric with the currency check box "checked" the value displays with as many trailing zeros (0) as the field box is wide. What gives?

How do I get it to display like $199.99? as opposed to $199.990000000000. I've done a Format Expression as $9,999,999.99 which displays as $ 199.99 (a whole bunch of space between the $ and the number)