I installed Baldur's Gate II from the GOG installer, played the game for a
while without problems. One day it decided not to respond when trying to rest,
forcing me to restart the computer (alt-tabbing did nothing). When doing this
every save of that session was ignored (does the game write the save files
permanently upon closing the game?).
What I did was reinstalling the game from the GOG installer. Save folder is not
modified. It's annoying if you have the widescreen mod or fixes installed,
but better than not being able to rest at all, and only takes about a minute.
I searched alot for information on this, but didn't find any so this will
have to do in the meantime.
Extra info: It also showed a not responding black screen when dying, so it seems
like the movies are somehow troubling the game. I changed the movies to 0 in the
baldur.ini file, but for some reason the movie settings always reset themselves.