After rewatching lots of episodes this weekend, I think I found a big answer to what some are viewing as a "continuity" error, and some other tidbits as well.
What got a lot of people ticked off about Across The Sea was the age of the Adam and Eve skeletons. In the season one episode In Translation Jack estimated the age of the skeletons to be 50 or so years old. And he was right with his estimate. But they died in 43 A.D. or so...how is that possible? Here's how...
When Ben turned the donkey wheel the island was skipping around in time, and Sawyer and the other Losties were skipping around different timeframes. To the island itself, this was real island time. Picture the island as an actual entity, and it's age is based on it's history, not what actual date it is in. If I time travelled 50 years in the past when I was 32 and spent four years in the past, and came back to the present the exact moment I left, I would be 36. So at some point in time the island went back to a time probably about 46 years after MIB and his mother took their dirtnap. Give about 3 or so years for the Losties to be in Dharma time, and you have 50 years for the skeletons. The skeletons only aged 50 years because that's what happened on the island.
I also think I found the answer to why MIB posing as Christian led Jack to the water in the caves. He didn't lure him there so the survivors could survive by finding fresh water. The water in the caves leads to the light, so he wants Jack to remember that, which will probably occur in the finale.
One other thing people were curious about was the timeframe for the Tarawet statue. Was it already there when Claudia got to the island? I believe it was. When Sawyer and the other Losties were dropping Locke into the well, they flashed to a time where there was no well and the statue was there, which leads me to believe the Egyptians were there before the Romans, which would account for the weaving the mother was doing.
I hope this sheds some light on a few things, no pun intended! And I have to say, I have watched Across The Sea a few times, and it gets better with repeated viewings.