Problem with SQL 2K DTS in VB

I am currently working on a project which need to transfer data from dBase V dbf file(con - DSN) to SQL Server(con - OLEDB). I have design the program to use MS SQL DTS, it is fastest as I know. The problem I'm facing right now is that as the table growth, the performance getting slower and slower, especially when I tried to delete record from the table before the transform task begin. currently the stats is 20,000,000 within 60 minute, but it is getting worse. Any one can give me better idea on how to solve this problem?