The reason I asked, is because I too have had very erratic behavior on grids especially using multitable related fields. In my most recent case, I need to sometimes interactively create a link to match related data from the parent to the child table (In case the child table does not have the matching field, it is created on the spot). But what happens is the indexes go awry, and all kinds of mixed up data fill up the grid, with no correlation to the parent data. A reindex at this stage would have been v. useful!