Strange issue

I facing a strange issue. I have following code which working fine when I login with admin and but when I login with some other account it doesn't work.  Code is to get an array of all the child requirement of a given req 1111

call to with some Req ID say 1111 

GetReqList(1111)

Function GetReqList(father_id)
    Set rfact = TDConnection.ReqFactory
    Set rfilter = rfact.Filter
    dim Index
    Index =0
    FilterText = "not (" & father_id
    Requirements_List = Array(father_id)
    GetChildren rfact, rfilter, father_id
    FilterText = FilterText & ")"

End Function

Sub GetChildren(rfact, rfilter, father_id)
    Set children = rfact.GetFilteredChildrenList(father_id, rfilter)
   dim Index
   Index=0
   For Each child in children
        Index = UBound(Requirements_List) + 1
        ReDim Preserve Requirements_List(Index)
        Requirements_List(Index) = child.ID
        FilterText = FilterText & " or " & child.ID
        GetChildren rfact, rfilter, child.ID
  Next

End Sub