“More” is messing up page formatting

I love using the “more” code to truncate our rather lengthy pieces. I have used it regularly with no problems. Now, for whatever reason, when I insert that tag my right sidebar winds up at the bottom of the page. It goes away as soon as the “more” code is removed. I have tried using the code in different posts to see if there was something going on with recent posts. It doesn’t matter if the post has a picture, no picture, is longer, shorter, has any special elements in it or not.

Go figure. Nothing has changed recently on my blog. I am all updated. I have no other glitches or weird issues going on.

Any clues, ideas, or voodoo you can recommend I will gladly listen. This one has me stumped.