PLEASE HELP - Append Qry Is Duplication Records

I have two tables.

Table one - tblContent
Table two - tblConentImport

I have built a select query that will identify all records that from the tblConentImport table that do not already exist on the tblContent table.

Here is the SQL -
SELECT [tblConentImport].[ID], [tblConentImport].[LoginName], [tblConentImport].[Title], [tblConentImport].[Type], [tblConentImport].[Code], [tblConentImport].[Date Assigned], [tblConentImport].[Date Started], [tblConentImport].[Last Accessed], [tblConentImport].[Progress], [tblConentImport].[Date Completed], [tblConentImport].[Time Spent (min)], [tblConentImport].[Score], [tblConentImport].[Result]
FROM tblConentImport LEFT JOIN tblContent ON ([tblConentImport].[Code]=[tblContent].[Code]) AND ([tblConentImport].[Type]=[tblContent].[Type]) AND ([tblConentImport].[Title]=[tblContent].[Title]) AND ([tblConentImport].[LoginName]=[tblContent].[LoginName])
WHERE ((([tblContent].[LoginName]) Is Null) And (([tblContent].[Title]) Is Null) And (([tblContent].[Type]) Is Null) And (([tblContent].[Code]) Is Null));

I then built an append qry that appends the new records to the tblContent table.

Her is the SQL -

INSERT INTO tblContent
SELECT [qrySelectContentTable].[LoginName] AS LoginName, [qrySelectContentTable].[Title] AS Title, [qrySelectContentTable].[Type] AS Type, [qrySelectContentTable].[Code] AS Code, [qrySelectContentTable].[Date Assigned] AS [Date Assigned], [qrySelectContentTable].[Date Started] AS [Date Started], [qrySelectContentTable].[Last Accessed] AS [Last Accessed], [qrySelectContentTable].[Progress] AS Progress, [qrySelectContentTable].[Date Completed] AS [Date Completed], [qrySelectContentTable].[Time Spent (min)] AS [Time Spent (min)], [qrySelectContentTable].[Score] AS Score, [qrySelectContentTable].[Result] AS Result
FROM qrySelectContentTable;

This works great as long as the [tblContent].[type] is not equal to "Class".

This select query and append query have not created duplicate records in my tblContent

Please help me. I'm loosing my mind. Below is the address to view this database. The select qry is named - qrySelectContentTable. The append qry is named qryAppend Content Table.

http://briefcase.yahoo.com/turnerbkgabrobins

Any help you can provide will be greatly appreciated.