On my husband's blog, on the writer, the buttons under both the visual and the code tabs do not appear/work. He hasn't made any changes. I added new plugins, but most I also loaded to my own, which works fine. The new ones only on his site:
Around this date in the past... - Widget Edition
KB Countdown Widget
I'm not sure if any of that's related, I just can't think of any other changes made to Adam's blog lately.