We played a multiplayergame with patch F and got OOS every time someone would actively attack other units.
We started multiple games - the problem persisted.
A suggestion: It seems to me that the Svartalfar aren't different enough from the Ljosalfar...just the "evil" version with few other real changes. Playing on Faeryl's status as the "Winter Queen" and the attendant lore I might suggest that Svartalfar units be given the Winterborn promotion to reflect their affinity for wintery conditions. And if Winterborn doesn't automatically grant a work speed bonus on tundra and ice/snow is there a way to make it do so? I already suggested to Jean Elcard in the FlavourMod thread that it might be a good idea to give the Svartalfar an affinity for forest/tundra terrain and the Ljosalfar an aversion to tundra terrain to solve an issue brought up by another player in which the Ljosalfar seemed to often end up in tundra due to their forest affinity and the fact that many tundra squares are forested.
I'm not sure there's a need for that much more differentiation (the two civs really do play very differently already) but the Winterborn for the Winter court is an interesting point. The main sticking point there would be that Elves are naturally weak vs cold (-25% resistance) so the Winterborn would only make it less of a penalty rather than a bonus, though the Tundra/Ice benefits would remain...
I don't think the Winter Court should be made to have bonuses in the cold weather terrains. They didn't rule colder areas, they ruled the same lands in the winter. They were upset by this because it meant that they only ruled when the weather was not conducive to getting anything done. Faeryl would clearly have preferred to rule in the Summer.
You can keep playing the old version without any issue, even if you already deleted your copy of FfH 2.034. New features from 040 will not be a part of FF until we release an updated version though.
Are you getting closer to improving game/processing speed?