cfgridcolumn, mask

My form is format="flash"

I have not found a solid post with a solution for formatting a gridcolumn type="currency" using the mask="".  What is odd is on the same row from the query one column is great $10.45 and the next column is 10.35000898979.  I dumped the query and the values there are 10.45 and 10.35 .  I tried the mask="$9,999.99"  but is just does $9,9999.9910.35000898979 in the column.  Any suggestions would be welcome.