redi api snapshot with duplicate orders

I noticed that my redi snapshot orders have duplicates and some doesn't have AvgExecPrice set. In my case, later updates overwrite AvgExecPrice.
Snapshot of orders:
row 0 OrderRefKey:[NONE] ExecPrice:[]
row 1 OrderRefKey:[gS01164921] ExecPrice:[0]
row 2 OrderRefKey:[gS01164921] ExecPrice:[]
row 3 OrderRefKey:[gS01164921] ExecPrice:[]
row 4 OrderRefKey:[gS01168421] ExecPrice:[107.04] <----------
row 5 OrderRefKey:[gS01179521] ExecPrice:[0]
row 6 OrderRefKey:[gS01179521] ExecPrice:[]
row 7 OrderRefKey:[gS01179521] ExecPrice:[]
row 8 OrderRefKey:[gS01168421] ExecPrice:[] <---------
row 9 OrderRefKey:[gS02114721] ExecPrice:[0]
row 10 OrderRefKey:[gS02114721] ExecPrice:[]
row 11 OrderRefKey:[gS02114721] ExecPrice:[]
End of orders

My redi id is r152885
case (int)CacheControlActions.Snapshot:
// Snapshot of what happened throughout this day
// expect this first
try
{
System.Diagnostics.Debug.WriteLine("Snapshot of orders:");
for (int i = 0; i < row; i++)
{

OrderRefKey = GetCell(rediCache, i, "OrderRefKey", out errCode).ToString().TrimStart();

ExecPrice = GetCell(rediCache, i, "AvgExecPrice", out errCode).ToString().TrimStart();

System.Console.WriteLine(string.Format("row {0} OrderRefKey:[{1}] ExecPrice:[{2}]", i, OrderRefKey, ExecPrice));