You're right when you say that text and memo fields are now stored as
Unicode format in Access. (UTF16 by default; if you chose with compression
mode, UTF8 will be used).
SQL-Server is capable of using both types: Unicode and Ascii and when you
make an insert, it will convert the text to the proper type. Proper
conversion should also be done if you are updating the database through a
linked table.
However with types such as the "OLE Object", Image and Binary fields, there
will be no conversion of the data. The fields are usually used for storing
things like images or text fields in an unsupported mode for the SQL-Server,
such as UTF8.
I suppose that there is some mixe-up at this level.
It's also a fact that using Access to interpret the schema of the SQL-Server
database might lead to some misunderstanding about the real type of the
field as it is stored on the SQL-Server.
You will have to be more explicit about this third party software, what you
are doing exactly and what are the real type of the field. Consulting the
web site of this third party software and using a tool such a SQL-Server
Enterprise Manager (for SQL-Server 2000) or SSMS (for 2005) will tell you
exactly what's going on.