2 separate issues for this;
The first - I posted to the old forum at the time (since it came up first when doing a google search) - thought I'd mention here assuming it wouldn't have been looked at on the old forum - M4 of the UEF campaign on co-op is bugged with 2 players (but not 1) where the map won't expand - I tried it several times and had the same issue.
Link to old forum containing replays:
The second issue: The leaderboard doesn't seem to work - none of the games I've played show up. For example, my latest game (replay ID #13792193) I completed M1 UEF in 13m 25s (1 player) but can't see my name anywhere on the leaderboard. Every time before I've played a co-op and then looked after completing the map I've also not been able to locate the game (some time ago though so I dont have the replay IDs)