hidden columns and groupBy with stat_total

I have a grid with 2 hidden columns. (I am setting the column hidden in the xml itself). I am also grouping the grid and doing a stat_total on a column, but because of the hidden columns the stat_total is not coming above the correct column. Is there a way to solve this? Thanks

Problem confirmed
Version of “_group” extension , which works correctly with hidden columns sent by email ( most probably similar fix will be released as part of next update )