I am Surak wrote:
But Ms. Blalock said she was under the weather and I want to believe her.
It wasn't simply something that Blalock "said." I read an article (startrek.com, I think) that reported that, as filming commence for Season 4, many members of the cast and crew, including Blalock and Dominic Keating, were hit by a powerful intestinal virus - including, IIRC, knockdown fatigue, not being able to keep food down, dehydration, and weight loss. It appears to have hit Blalock particularly hard, which explains her gaunt appearance in the first several episodes of Season 4.
By the way, doesn't anyone else think that "All About T'Pol" means more than "All About T'Pol's Bosom"? There are a number of other
aspects to the character.