How do I determine ADO's capabilities?

ADO is dependent upon the data provider it uses. The easiest/quickest way is to check the Supports property to confirm that the connection or recordset you opened supports the functionality you actually need. You should also confirm that the CursorType, and LockType match what you expected. If the underlying provider cannot support the cursor you requested, ADO downgrades these properties to get the cursor that is closest to what you requested.