Moises,

I had to develop a rebuilding class which would do the pack, the reindexing and even the rebuilding of the database files.

I do it by opening ( in my case ) the .DBC's exclusively before doing anything else. If all goes well then I start working on the .DBF's - the other users receive an error stating what is going on if they are trying to get in. You could do the same with your tables, before packing them on.

I hope this helps.

Carlos