As you’re all aware, Apple released OS X 10.5.3 Wednesday, and I wrote an analysis piece on the update. However, after looking at my blog post late Wednesday, I realized that I had made a fundamental mistake in writing about what’s changed in 10.5.3: I wrote about the wrong update file. How did this happen, you might wonder?

I have a few machines here in the house, and whenever Apple releases an update, I update most machines using the built-in Software Update. However, I also like to download the Combo Update, and use that on at least one machine—in the past, people have experienced different results when using the Combo Update instead of Software Update, so I like to try both and compare the results.

I also make text files out of the “bom” files that the installers generate, so I can easily read and search them in a text editor. I did that yesterday, too, with both the Combo Update and Software Update installer boms (as explained at the end of my article). I then put both text files on one machine, so I could look at them side-by-side. (You can probably guess what happened next.) When I then started working on my article about the changes in 10.5.3, I wrote it based on what I was reading in the bom file from the Combo Updater, instead of the bom file from Software Update.

Why is this a problem? Technically, nothing I wrote Wednesday was incorrect—all those files are modified by the 10.5.3 updater, but they’re modified by the Combo Update, not the version most people will get via Software Update. So what’s the difference? The Combo Update can update a machine running any version of OS X 10.5 to 10.5.3—so it needs to include all the files that have been modified by any update since 10.5 was released. I’m very sorry for making this mistake, and in the interest of setting the record straight, here are the corrections to my original article based on the actual 10.5.3 update file.

- I wrote that “Networking technologies are updated, as are file systems such as NTFS, SMB, UDF, and WebDav.” While networking technologies were indeed updated, the file system updates occurred in a prior 10.5 update.

- The Dashboard widgets that received new code in 10.5.3 are the iCal widget, Unit Converter, and Weather.

- The Web Clip widget received updates only to its non-English language files.

- Macromedia’s Shockwave plug-in was not updated in 10.5.3.

- While iSync was updated in 10.5.3, those updates did not include new Samsung phones.

- Regarding the long list of updated applications, the following apps were not updated in 10.5.3: DVD Player, Activity Monitor, ColorSync Utility, Keychain Access. Preview was updated, but not for PDF and images as I noted in the original article.

- The actual number of changed files is “only” about 21,000, not the 35,000 I noted in the original article.

Again, my sincere apologies for making such a stupid mistake. I will never again open two bom files for two different updates on the same machine while also writing about said update.

Note: This blog first appeared on our sister site macworld.com