I'm trying to use the WebDateTimeEdit with a UltraWebGrid

I set the WebDateTimeEdit as the control of a columns grid...

When I put a date like 20/03/2008 (My system is dd/mm/yyyy) it's fine....but when I try to edit the value....the value turns blank....it seems the control have turned back to the culture mm/dd/yyyy and recognize that the month is > 12......but when I set the date to 20/03/2008 it allows again....

Another problem is when I put a date like 10/03/2008, this time when I try to edit the date it doesn't turn blank...but the date becomes 03/10/2008....and if I leave the edit mode and try to edit again, the value turns back into 10/03/2008....and this is a loop!!