- Is there a reliable source for this fact?
- Which printings of the Mishna B'rura — and other books, if any — did he do this to?
The Chofetz Chaim sighed deeply and said, "I too am a person who makes mistakes. You know that I sell my books. Sometimes the binder misplaces a page, or a page might be missing or have unclear print. Even though I am careful to check every book before it is sold, there still could be mistakes. The people who buy my books are embarrassed to tell me when there is a defect, but in their hearts they really care, and that is why I was also punished."
In the Kollel Yad Shaul in Johannesburg, they had a volume of the Mishna Berura with the word מוגה in the front cover.
It was an early copy - very early 1900's IIRC.