SQLite Very Slow in Saving

I have a database with over 30,000 rows and 31 fields. (154MB) I had to change the format of 1 field from a vb.net application then save the datatable back to the SQLite database using the following:

Dim cb As New SQLiteCommandBuilder(RawSalesAdapter)
RawSalesAdapter.UpdateCommand = cb.GetUpdateCommand
RawSalesAdapter.Update(DTRawSales)

This process takes over 2 hours to save?? Can you see what I am doing wrong?

Thanks for your help Brad