Unicode Issue in App post Oracle to SQL Migration

I posted this on the .NET forum last week and have received no responses. Hoping someone can help through this forum.

I have a .NET application that accepts user input in 5 languages: English, Spanish, Thai, Polish, and Chinese.

The application functioned properly against Oracle, but now that the data has migrated to SQL Server the Thai, Polish, and Chinese information entered by the user in the application appears as "??????" in the database post insert.

I can insert these languages directly into the database (through management studio) and I can pull the languages from the database to the application correctly so that tells me the database is configured properly.

The app also accepts the input correctly prior to calling the insert, so it appears the issue occurs when passing the values between the app and the database.

The web.config contains the following globalization setting:
<globalization requestEncoding="utf-8" responseEncoding="utf-8" fileEncoding="utf-8" />

The code-behind has the following:
Imports System
Imports System.Data
Imports System.Data.SqlClient

Is there something else required to successfully pass unicode from the app to SQL Server 9.0.3073?

Thank you.