I got an empty gift from Ethiopia. IIRC it was probably because I had just made peace with Byzantium, as Haile Selassie said it was to support my war efforts, even though I was no longer in war. I might be wrong though, since the game took place a week ago, but I'm fairly sure of this. Both me and my friend got several trade offers by AI and AI also DOWed us a few times. I don't remember any of the deals causing CTDs. This was with 4/9.
BTW, everything worked very well even with EUI (but no barbs). I guess we got just one CTD during the first 100 turns. At around turn 180 we started to get several of them, as we both got into a war (my friend fought against 2 enemies, I had just one opponent). Don't know if it had something to do with CTDs that around the time we found each other's continents. For some reason, earlier wars didn't cause CTDs, or they caused much less of them.