PMFJI-
First off, grid data should be table buffered.

The current record number (recno()) does not change when I use up/down arrow on the scroll bar
No, it won't because, because you haven't actually changed the current row (and therefor record number. Same with the thumb. I created a grid attached to a table with optimistic row buffering (normally, I'd use table).

I clicked on random row, and changed a field. I then "thumbed" through the grid and then issued a tablerevert() which did infact revert the change I'd made. I admit that in the debugger the recno *appears* to changes briefly, but does remain the same.