Duplicate login items

After completing a fresh 10.5.5 install on my hackintosh (part 2 coming soon) I had a poke around the system preferences to find anything that wasn’t working as expected. One thing that surprised me was the login items section of my user account. The screenshot below shows part of the massive list of login items.

The scroll bar on the right gives an idea of how long the list was, I counted around 60 items. Most were duplicates, and apart from iDriveMonitor and GrowlMenu there were several copies of Firefox, iTunes Helper, Mail and many others. I don’t think this was caused by copying my user account from the backup drive to the fresh install using Migration Assistant, as many of the duplicate apps were not on the fresh install. The only cause I can think of is updated apps adding themselves to the list without removing the existing entry. I occasionally stop Mail.app and Firefox from opening when I log in, so this could explain their multiple entries.

The image above shows the list while I worked through it removing the duplicate entries. The final image below is the pruned list with the correct entries. I got the list down from 60 to 15. My biggest concern was how much extra time this would add to the start up time, but it doesn’t appear to have made any difference as the apps in the list seem to run one instance and ignore further attempts to launch. When I checked using Activity Monitor there were no more than one instance shown.

This appears to be a strange occurrence more than a problem, so I would be interested to hear from anyone else who has encountered this issue. It would be nice to know if it is a hackintosh specific problem or just another of Leopards bugs.