>>What approach you are using in displaying records in the grid?
>>Is it via One-to-Many relationship or just filtering the child by
>>SET FILTER command?
>
>It is by a SET RELATION from the parent table.
>When I look at records in the browse windows,
>the relation is working fine. Child records display
>when the parent record is highlighted.

I guess somewhere in your underlying code loses the proper index key that makes the relationship intact.

There are 3 ways to achieve relationship in the grid:

1. Using SET RELATION command.
2. Using the Grid's ChildOrder, LinkMaster, RelationalExpr properties.
3. DE

If you do not prefer DE, use no. 2, it is better, faster, and safer.