[RESOLVED][02/03] Error moving images after using to create new .tiff

I have a process that goes out and downloads a list of images:
imageabc_1.tif
imageabc_2.tif
imageabc_3.tif

As these images are saved I add the name to a collection. Once all images are saved I call a function (imgNew = CombineImagesNEW(colImgList, DownloadPath)) to take all images and combine into one file.

I then have a process that moves all temp images to a 'old' folder. My first image I have no problem moving but all other images I get the following error:
System.IO.IOException: The process cannot access the file "c:\.....image_2.tif" because it is being used by another process.

I was thinking it has something to do with the section of saving the intermediate frames in my CombineImagesNEW function but I can't figure out where I am not closing it.

Any advice is welcome.

VB Code:

Public Function main()
'..... REMOVED CODE
Select Case colImgList.Count
                Case 0
                    'Something must be wrong.
                    bReturn = False
                    Return False
                Case Else
                    Try
                        'More then two images so need to call looping CombineImages function to put all in one.
                        'Tried just saving ImageFormat to .jpeg but didn't work.
 
                        Dim imgNew As Image
                        imgNew = CombineImagesNEW(colImgList, DownloadPath)
                        bReturn = True
                        imgNew.Dispose()
                        imgNew = Nothing
                    Catch Ex As Exception
                        bReturn = False
                    End Try
            End Select
 
            'REMOVE ALL TEMP IMAGES TO OLD FOLDER
            Dim sMoveName As String
            Dim iImageLoop As Integer
            For iImageLoop = 1 To colImgList.Count
                Dim sCurrentImgName As String
                sCurrentImgName = Convert.ToString(colImgList(iImageLoop))
                'Make sure file is found before doing a move.
                If File.Exists(sCurrentImgName) = True Then
                    sMoveName = sCurrentImgName.Replace(Name, Name & "\old")
                    If File.Exists(sMoveName) = False Then
                        File.Move(sCurrentImgName, sMoveName)
                    Else
                        'File already exists so need to change filename so has datetime at beginning
                        File.Move(sCurrentImgName, sMoveName.Replace("\old\", "\old\" & Now.ToString("yyyyMMdd_hhmmss") & "_"))
                    End If
                End If
            Next
 
            Return bReturn
        End Function
 
Public Function CombineImagesNEW(ByVal colImageList As Collection, ByVal sPath As String) As Image
    Dim iImgCnt As Integer
    Dim iImageLoop As Integer
 
    iImgCnt = colImageList.Count
 
    'get the codec for tiff files
    Dim info As ImageCodecInfo = Nothing
    Dim ice As ImageCodecInfo
    For Each ice In ImageCodecInfo.GetImageEncoders()
        If ice.MimeType = "image/tiff" Then
            info = ice
        End If
    Next ice 'use the save encoder
 
    Dim enc As Encoder = Encoder.SaveFlag
    Dim ep As New EncoderParameters(1)
    ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.MultiFrame))
    Dim pages As Bitmap = Nothing
    Dim frame As Integer = 0
    Dim s As String
 
    frame = 1
 
    'Loop through collection to put all images into one main image.
    For iImageLoop = 1 To iImgCnt
        If iImageLoop = 1 Then
            pages = CType(Image.FromFile(Convert.ToString(colImageList(iImageLoop))), Bitmap)
            'save the first frame
            pages.Save(sPath, info, ep)
        Else
            'save the intermediate frames
            ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.FrameDimensionPage))
            Dim bm As Bitmap = CType(Image.FromFile(Convert.ToString(colImageList(iImageLoop))), Bitmap)
            pages.SaveAdd(bm, ep)
            bm = Nothing
        End If
 
        If frame = iImgCnt Then
            'flush and close.
            ep.Param(0) = New EncoderParameter(enc, CLng(EncoderValue.Flush))
            pages.SaveAdd(ep)
        End If
        frame += 1
    Next
 
    Return pages
    
End Function