I have several missions, made with Fred 3.6.9, that have issues with briefing icons when played with Fs2 3.6.10. All of the icons are moved much, much closer together. When I go back and view the briefing with Fs2 3.6.9, everything is fine and dandy.
I had to manually load all of my missions in Fred 3.6.10 (where the icons also show up botched) and spread everything out much further to get 3.6.10 to render the briefing properly (it still scales the spacing down, took me loads of trial and error). When I load the changed mission back into 3.6.9 Fs2, the briefing icons appear too far apart.
Apparently 3.6.10 FRED has some sort of bug with the mission icons.
It is noticable in all missions, but ESPECIALLY in missions made with 3.6.9 FRED but played in 3.6.10 Fs2.