GAL Photos in Exchange 2010 and Outlook 2010

I'm trying to make a simple uploading application in Visual Basic.Net. I have most if it working... I can choose a user, I can select part of a photo, and I can save that to AD. I can retrieve that data out of the thumbnailPhoto attribute and display that picture back into VB.net. I can even use it as embedded data in PHP, but for some reason it's not displaying in Outlook 2010. Anybody have an brilliant ideas? Here's some relevant code (note: this is partial code, not the whole app):

-------------------- Saving to AD in VB.net -------------------------
       Dim myUser As New DirectoryServices.DirectoryEntry("LDAP://" & userDN)
       Dim stream As New IO.MemoryStream
       Dim img As Image
       Dim ptr As IntPtr

       ' Clear any existing photo
       myUser.Properties("thumbnailPhoto").Clear()

       ' Make sure our size is 96x96
       img = picPreview.Image.GetThumbnailImage(96, 96, thumbnail_abort, ptr)

       ' Convert the img to a byte array for storage in AD
       img.Save(stream, Imaging.ImageFormat.Jpeg)
       Dim b(stream.Length) As Byte
       stream.Position = 0
       stream.Read(b, 0, stream.Length)

       ' Store the image
       myUser.Properties("thumbnailPhoto").Add(b)
       myUser.CommitChanges()


------------ Retrieving from AD in VB.net -------------------

       picOriginal.Image = Nothing
       Dim myUser As New System.DirectoryServices.DirectoryEntry("LDAP://" & userDN)
       Dim b() As Byte
       b = myUser.Properties("thumbnailPhoto").Value
       If b IsNot Nothing Then
           picPreview.Image = Image.FromStream(New IO.MemoryStream(b))
       End If

--------------- Using as a data URL in PHP --------------------
[[ $u is populated from the ldap_get_entries() function ]]
<img style='float:left; padding-right:5px;' src='data:image/jpeg;base64,".base64_encode($u['thumbnailphoto'][0])."'>

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As mentioned above, both of the retrieval functions display the thumbnailPhoto as expected, but it's still not showing up in Outlook. I double checked the schema change mentioned above and I know for sure the PHP code is using data from the Global Catalog.