Problem in Sort

Hi, 
I have a problem with RadGrid with Persian Language. 
In Persian there is 2 types of first letter like < آ > and < ا >.
The first type < آ > should be prior when sorting(upper in ascending sort). But in action, < ا > stands upper than < آ >.
I use Persian_100_CI_AS Collation.
Same query in SQL server returns fine order.