Hi!

As VFP do scanning, it get more and more memory for buffers. Finally its up to the swapping in HDD that cause slow down. Try to use FLUSH periodically, say, each 100 records.
Another reason is insert command for table with indexes. When table3 have a lot of indexes, each nex insert become slower and slower.

>....code after tables have been opened
>
>SELECT Table1
>SCAN
>REPLACE Field1 WITH FieldValue IN Table1
> IF SEEK(Field2, "Table2", 2)
> IF Table2.Field1 = .T.
> INSERT INTO Table3 blah blah blah.....
> ENDIF
> ENDIF
>ENDSCAN
>
>There you go, basically what it is doing.
>
>Kev