Existing users, 
The StuffIt Expander 13.0.2 installer offers the choice of removing (or not) the old StuffIt folder containing all of the StuffIt apps. Choosing not to remove it moves the old folder and the StuffIt CM plugin to the trash and writes a new StuffIt folder, which contains only StuffIt Expander 13.0.2 and StuffIt manual, in the Applications folder.
After completing installation, it is necessary to manually (1) move the plugin back to the Library:Contextual Menu Items folder, (2) remove the old StuffIt folder from the trash, (3) replace the old StuffIt Expander app with the new one and (4) then replace the new StuffIt folder with the old one in the Applications folder.
While I did not try to install by removing the old folder, I believe that doing so would result in the loss of all StuffIt apps and functionality except StuffIt Expander 13.0.2.
Smith Micro could have thought this one through a lot better.
StuffIt Deluxe
Compress, send, and share large files online.
Version: 2010
WARNING
Feedback Type: Troubleshooting Report
Contributed by: Robert Welch Friday, November 07 2008 @ 10:05 AM PST
Product Platform: MacOSX
Used Product For: Over One Year
System Info:
Comments
WARNING - Robert Welch
Running VersionTracker identified only StuffIt Expander as having a newer version and when I clicked the download button, it downloaded only the Expander 13.0.2 installer, which resulted in the strange behavior I described.I posted my comment to alert others to the issue I experienced believing that it might help prevent problems. I am pleased that you did not experience the same problems.
Thanks for letting me know that there is a full StuffIt Deluxe release 3 update available. I ran the installer successfully.
I apologize for any inconvenience that my post may have caused.
Friday, November 07 2008 @ 07:24 PM PST
WARNING - DavidPabian
That explains it. I've run into problems like that with the VT app. I found the update on the site itself, so didn't run the pro app. That was definitely an annoying glitch for you... and now it's my turn to apologize for not figuring out how your problem arose through some sloppily programed version tracking itself.Saturday, November 08 2008 @ 11:27 AM PST
WARNING - DavidPabian
Since this is the StuffIt Deluxe application, not StuffIt Expander, I'm not sure why the poster's comment is here and not on the Expander page, but I had no problem with the Deluxe install. The folder was replaced with all the updated apps and the plugin was also installed. Why would anyone just update Expander and not the other files unless there was a problem understanding the difference between Expander and the full Deluxe package when first downloading from VT? This update worked fine for me, with all necessary files in place.Reply to This
Friday, November 07 2008 @ 01:01 PM PST