OK, here we go - below you'll find the entire sub:

Sub showCalItems(StartDate As Date, EndDate As Date)
On Error Resume Next
   Dim myRestrictItems As Items, strTxt As String
   Dim myCalItem As AppointmentItem, NodesCal As Nodes, nodX As Node
   Dim NodXI As Node, itemStart As Date, itemEnd As Date, lDate As Date
   Dim objCDO As Object, intIcon As Integer, intDayIcon As Integer
   Dim strIncr As String, I As Integer
   Dim intWeek As Integer, objRecurPattern As RecurrencePattern
   Dim strTempArrayText As String

   Const omHourAndMinute As String = "hh:nn"
   Const omNullHour As String = "00:00"
   Const omDayEnd As String = "ddddd 23:59"
   Const omFullMoon As String = "fullMoon"
   Const omNewMoon As String = "newMoon"
   Const CdoPropSetID1 = "0220060000000000C000000000000046"
   Const CdoAppt_Colors = "0x8214"
   Set objCDO = CreateObject("MAPI.Session")
   objCDO.Logon "", "", False, False
   With
Application.GetNamespace("MAPI").GetDefaultFolder(olFolderCalendar).Items
       .Sort "[Start]"
       .IncludeRecurrences = True
       Set myRestrictItems = .Restrict("[Start] >= '" & _
           Format$(StartDate, "mmm-dd-yyyy 00:00") & "' And [Start] <='" &
_
           Format$(EndDate, "mmm-dd-yyyy 23:59") & "' Or [End] >= '" & _
           Format$(StartDate, "mmm-dd-yyyy 00:00") & "' And [End] <='" & _
           Format$(EndDate, "mmm-dd-yyyy 23:59") & "' OR [Start]<'" & _
           Format$(StartDate, "mmm-dd-yyyy 00:00") & "' AND [End]>'" & _
           Format$(EndDate, "mmm-dd-yyyy 23:59") & "'")
   End With
   With frmViews
       Set NodesCal = .treeCtl.Nodes
       .treeCtl.ImageList = .ImgList
   End With
   With NodesCal
       .Item(.Count).Selected = True
       .Clear
   End With
   For lDate = StartDate To EndDate
       If intWeek <> 0 Then Set nodX = NodesCal.Add(, , Format$(lDate,
"ddddd") & "a", vbNullString)
       If intWeek = 0 Or intWeek <> Format(lDate, "WW", vbMonday) Then
           intWeek = Format(lDate, "WW", vbMonday)
           Set nodX = NodesCal.Add(, , Format$(lDate, "ddddd") & "w", _
                String(22, 175) & " Week " & intWeek & "  (" & 52 - intWeek
& ")")
           nodX.Bold = True
       End If
       Select Case lDate
           Case Date
               Set nodX = NodesCal.Add(, , Format$(lDate, "ddddd"), "ToDay
(" & Format$(lDate, "dddd d.mmm") & ")", intDayIcon)
'                NodX.BackColor = RGB(255, 200, 200)
           Case Is < Date
               Set nodX = NodesCal.Add(, , Format$(lDate, "ddddd"),
Format$(lDate, "dddd d. mmm"), intDayIcon)
               nodX.ForeColor = RGB(150, 150, 150)
           Case Is > Date
               Set nodX = NodesCal.Add(, , Format$(lDate, "ddddd"),
Format$(lDate, "dddd d. mmm"), intDayIcon)
       End Select
       With nodX
           .Bold = True
           .Expanded = True
           If Weekday(lDate, vbMonday) > 5 Then
               .ForeColor = RGB(255, 0, 0)
           End If
       End With
   Next
   For Each myCalItem In myRestrictItems
       With myCalItem
           itemStart = .Start
           itemEnd = .End
           If itemEnd > itemStart And Format$(itemEnd, omHourAndMinute) =
omNullHour Then
               itemEnd = Format(itemEnd - 1, omDayEnd)
           End If
           If itemStart < StartDate Then itemStart = StartDate
           If itemEnd > EndDate Then itemEnd = EndDate
           If .IsRecurring = True Then
               intIcon = 9
           ElseIf .ReminderSet = True Then
               intIcon = 10
           Else
               intIcon = 2
           End If
           For lDate = DateValue(itemStart) To DateValue(itemEnd)
               I = I + 1
               If DateValue(itemStart) = lDate Then
                   strTxt = Format$(itemStart, "hh:nn   ") & .Subject
               Else
                   strTxt = .Subject
               End If
               If Len(.Location) > 0 Then strTxt = strTxt & " (" &
.Location & ")"
               Select Case lDate
                   Case Date
                       Set NodXI = NodesCal.Add(Format$(lDate, "ddddd"),
tvwChild, _
                           .EntryID & Chr(I), strTxt, intIcon)
                   Case Is < Date
                       Set NodXI = NodesCal.Add(Format$(lDate, "ddddd"),
tvwChild, _
                           .EntryID & Chr(I), strTxt, intIcon)
                       NodXI.ForeColor = RGB(150, 150, 150)
                   Case Is > Date
                       Set NodXI = NodesCal.Add(Format$(lDate, "ddddd"),
tvwChild, _
                           .EntryID & Chr(I), strTxt, intIcon)
               End Select
               If .IsRecurring = True Then
                   Set objRecurPattern = .GetRecurrencePattern
                   If objRecurPattern.RecurrenceType = olRecursYearly Then
_
                       NodXI.Text = "(" & DateDiff("yyyy",
objRecurPattern.PatternStartDate, lDate) & " ?r) " & .Subject
               End If
               With objCDO.GetMessage(.EntryID, _
                   .Parent.StoreID).Fields.Item(CdoAppt_Colors,
CdoPropSetID1)
                   Select Case .Value
                       Case 0
                       Case 1
                           NodXI.BackColor = RGB(255, 180, 180)
                       Case 2
                           NodXI.BackColor = RGB(145, 145, 255)
                       Case 3
                           NodXI.BackColor = RGB(170, 255, 170)
                       Case 4
                           NodXI.BackColor = RGB(192, 192, 192)
                       Case 5
                           NodXI.BackColor = RGB(255, 182, 108)
                       Case 6
                           NodXI.BackColor = RGB(128, 255, 255)
                       Case 7
                           NodXI.BackColor = RGB(177, 177, 101)
                       Case 8
                           NodXI.BackColor = RGB(255, 220, 220)
                       Case 9
                           NodXI.BackColor = RGB(0, 166, 166)
                       Case 10
                           NodXI.BackColor = RGB(255, 255, 155)
                   End Select
               End With
           Next
       End With
   Next
   NodesCal(1).Selected = True
   NodesCal(1).Selected = False
   Set myRestrictItems = Nothing
   Set nodX = Nothing
   Set NodXI = Nothing
   Set NodesCal = Nothing
   Set objRecurPattern = Nothing
   Set objCDO = Nothing
End Sub

How did you instantiate myRestrictItems? With or without Sort and
IncludeRecurrences? It's awfully hard to try to duplicate an issue without
even knowing whether you're getting master AppointmentItem objects or
individual recurrences.