Unicode characters display as question marks, 'garbled' or 'nonsense' text in some Windows Form Controls even though they are stored in a personal geodatabase and display perfectly in ArcGIS products.
The Windows Form Control used to display the characters is not Unicode-enabled. This is known to happen in VB 6, VBA and VC++ 6.
Given that MessageBox is not Unicode-enabled, this VBA code may be used to reproduce the issue. Paste it in an ArcMap document and modify it as needed to work with your Unicode test data:
Dim pMxDoc As IMxDocument
Dim pMap As IMap
Set pMxDoc = Application.Document
Set pMap = pMxDoc.FocusMap
Dim pFeatLayer As IFeatureLayer
Set pFeatLayer = pMap.Layer(0)
Dim pTable As ITable
Set pTable = pFeatLayer
Dim pRow As IRow
Set pRow = pTable.GetRow(1)
theUnicodeText = pRow.Value(2)
MsgBox "value= " & theUnicodeText
The Windows Character Map tool, located in Start > Programs > Accessories > System Tools > Character Map, may be used to select and copy Unicode characters to the clipboard for pasting into the attribute table in edit mode.