I still think it has something to do with the fact that I deleted some items from the grid, and that caused something to happend.
Deleting some items, if they are parents of other items, cans sometimes have that effect.
Let's pick an example happening in the "Inbox" grid (if you still have it in your setting).
1- the grid's source corresponds to the "Inbox" field (ie : the Inbox field needs to be check for any item to appear in the Inbox grid, as it's originally set). Note that this field doesn't have the "value-->sub-item" option checked (in fields properties). It means that only the parents will have the "Inbox field" checked, not the children -- unless you decide otherwise on a case to case basis.
So : for an item to be displayed in the Inbox grid there can be 2 options : 1) the "inbox" field is checked, 2) or the item is to be the children/sub-item of a parent/top-level item already matching the grid's source (this is the case in SQLNotes default configuration).
2- in the "Inbox" grid, if you you delete some parents, their sub-items won't have parents anymore, and because they didn't necessarily have the "inbox" field checked (sub-items now don't meet the source as top-level items - unless you manually checked the "inbox" field or added the the items through the "add item" window ctrl-alt-n), will disappear from the grid too and will end up in... "no grids land".... They will still be in the database, just invisible.
: This is coherent with the "folder metaphor" : remove a parent and the chidren disappear to. Unless you move them elsewhere before you do so.]
complicated, and it is a bit... That's why I usually work with the "value-->sub-items" option turned on for most of my simple sources. It prevents these things from happening : If I delete parents from the grids, the children/sub-items still meet the source. If I turn the "flat view" option on : I see all items, even the sub-items. Etc.
There are a couple small drawbacks in using inheritance (value-->subitems) -- a bit more CPU intensive maybe, and a couple hierarchy display bug -- but not many. I've made the decision to stick to it. Much more coherent with the "add item" window which will automatically assign a specific field to new items, and allows one to have a true flat view of all items displayed in a grid -- essential to me. [EDIT
: the "value-->subitems" option can also more easily make some items appear in grids where you don't want them, if you're not careful; but this can be fixed "manually", as everything else!]