Whenever i shoot down a dreadnought, and send my dropship for ground combat, the game crashes to desktop when i click engage.
Tried it with the chinook, shrike and valkyrie, with and without tank, with different armors and weapons (Sentinel, predator, wolf and without armor), no effect.
Also, in late game ground combat, i often encounter ufos (always massive ones) with no aliens onboard, i can move my troops in first round, then i instantly win.