How to get rid of duplicate table where one is invisible C#

Question

I have a table where i did store data. But after adding some extra column in that table when i try to insert some value in the new columns it shows an exception that "invalid column name". But when i tried to insert value to the old column of my table it store the value and i can also retrieve those value in a form, But the newly added value cant be shown in the existing table. I think there is a invisible table in my default database schema with the same name of my dbo schema table. Where my data is being stored and retrieved.And in those visible table my newly added column has not been added that is why its shows this exception. Can any one suggest me what can i do to get rid of this problem?Really i am in a great problem.