also at the new city there was no issues untill i engaged in activity with another player, so figure it might be caused by some kind of packet loss corrupting the save due to the instability there is with the networking between players. so with steam launch and more players coming in, that instability will become more frequent, so it needs to be fixed some how. also our citys are probably not salvage able, so we would have to rebuild. if the networking can be sorted.
not a programmer or anything, but i did grow up with computers and have spent alot of time fixing them, and messing about.
anyways just my 2 cents, hope it can help in anyway