A Textual Error in the Book of Mormon

                We know from Alma chapter 22:31 – 32 that the Land Northward was called Desolation and the Land Southward was called Bountiful. We also know that a “line” separated them that was a day and a half's journey wide going from the East to West sea. Keeping that in mind, Helaman 4:6 says the Nephites were driven into the Land of Bountiful. In Helaman 4:7 we read that they fortified the "line" from east to west, it being a day's journey, to defend their north country. This seems to be the same place mentioned in Alma 22:31- 32. Helaman 4:8 says the Lamanites had taken possession of all the Nephites lands in the Land Southward. Thus, the Lamanites also possessed Bountiful in the Land Southward. Verses 9 -10 state that the Nephites regained about half of their territory. In the printer’s manuscript, and the 1830 edition of the Book of Mormon, the word "retained" was used, but this was changed to “regained” which seems clearer and correct. Thus, we see an example of a textual error in the original Book of Mormon. But, I believe another textual error exists that has not been changed. Bountiful is in the Land Southward and the Lamanites occupied all of it. The Nephites were fortifying the line between Bountiful and Desolation. Thus, Helaman 4:6 should read that the Nephites were driven even into the Land of Desolation, not the Land Bountiful. Comments?