As you have perhaps noticed, I recently installed a new Drupal theme, Nonzero. It is all fine and dandy, but the right sidebar was moving to the left as the text in it grew, and it started to run over the text in the posts, making the layout look bad (particularly in Opera, which I use).

If you are using this theme, the fix is simple. Just add width: 13.0em; to the #secondaryContent_2columns section of your style.css and now your sidebar will have a fixed width (you may also need to repeat this for #secondaryContent_3columns).

Overall I like the theme very much, even if it has some issues with links not having the right margins, pictures in comments not aligning, etc. Do try it out.