Just a shot in the dark -- you've opened the database exclusively, but is it possible that the "exclusive=yes" refers to the database but not to the individual tables (I know it sounds odd, as I said, just a shot in the dark).

So maybe try this:
ado.execute "use table1.dbf exclu"
ado.execute "pack"


>Hmmm I tried that and the new connect string was accepted as valid, but I still encountered the same problem when I try to issue a Pack command via the Ado.Execute method
>
>Maybe I'm going about this the wrong way...?
>
>Anyway I have a VFP database container (with tables) .dbc accessed thru ODBC, so I open an ado connection like so:
> ado.open "dsn=jas_data;exclusive=yes"
>
>When I write the following command:
> ado.execute "delete * from table1.dbf"
> ado.execute "pack"
>
>the 2nd line fails with an error message stating that it should be opened as exclusive. If I use "pack table1.dbf" instead, I get an error saying the file is in use.
>
>Any ideas...? (although I'm pretty sure I'm actually using the PACK command wrong here...)
>
>Thanks much!