First off, what is Kate's problem? She was insanely rude to Locke when he visited her in this episode. She tells him the reason he wants to be on the island so bad is because he doesn't love anyone. Which as any faithful Lostaholic would know, is completely untrue. Then, once Locke tells her that she is false in her accusation and explains what happened, Kate tells him that he is still an "angry and obsessed" old man. I thought this was really out of context for Kate, and I was really dissapointed with the way her character handled Locke's visit.
The second thing I was a little peeved by in this episode took place during the scene with Walt and Locke. If you remember back to season 4, Walt visits Hurley in the mental institution and tells him that Jeremy Bentham cam to visit him. Now in the scene with Walt and Locke in this episode, Locke never mentions that he is using an alias. So how does Walt know that Locke's code name is Jeremy Bentham. Either there is another scene yet to come with Walt and someone who knows that Locke is using the name Bentham or the writers screwed up. It's not the end of the world, and I'm probably just jumping to a conclusion, but Lost is known for having very few if any inconsistencies and I'd hate for them to make such a simple thing like a name drop ruin their clean slate.
Overall however, this was one hell of an episode and I can't wait for next week. I hope Locke beats the crap out of Ben for killing him. (that sounded wierd to say)