>>If I navigate from buyer to buyer while the buffer is dirty, it will crash (of course).

Use optimitic table buffering so you can change records without firing tableupdate(). Then update all at once.

I would use relations, but don't couple your grids directly to a table. Instead, I would use list controls and bind to an array then populate lists from array using list functions. Binding data directly to a grids or lists can can cause headaches.

Charlie