- LaunchDaemons: cannot login from admin account
- Permissions - apps cannot be updated
- Keychain First Aid 10.2 running on OS X 10.5
- The unknown user and group bugs
The Archive and Install form of the update process (this or clean install are the only safe choices, both have big issues) applied login items belonging to my wife's user account to my own account. I suspect it applied them to all accounts, but I haven't dug through the rest yet.
So her Missing Sync for Blackberry was running in my account -- at the same time as my instance of Spanning Sync was running (both products come from two unrelated and very good vendors).
Now I'm not a registered user of Missing Sync for Blackberry, so it shouldn't have run. But I am a registered user of a recently uninstalled verison of Missing Sync for Palm. Somehow remnants of both, whch both use the OS X sync services, interacted with an old Mark/Space data file that the Mark/Space uninstaller left in my library (I wish uninstallers were better at removing Library data folders, though this remnant might have been living in a Sync Services folder.)
This all caused a sync storm, with lots of reconciliation tasks. Unfortunately the current version of Spanning Sync doesn't give users much feedback about what it's doing, but that will change with version 2.0 (in beta).
I removed the errant login items and hunted down old Missing Sync data folders in my Library. The Sync Storm seems to be over, now I just have to clean up the wreckage.
Sync is hard. Bugs are bad. Sync bugs are the worst.
There's a broader lesson here, beyond my oft-expressed hope that Apple will concentrate on quality and bug fixes for 10.6.
Today's computers (I use XP at least as much as OS X, it's at least as bad) are absolutely not suited for non-geeks. I think my original DOS 2.1 computer was more non-geek friendly -- if only because it was so limited. The original Apple or Commodore GEOS systems were probably the best non-geek machines.
In some ways browser-based single vendor solutions are a move back to the limited power and relative simplicity of those days.
 Many of these bugs were fixed in 10.5.4 -- but as of a few months ago Apple still shipped 10.5.2 on their update/install DVD. So even those of us smart enough to avoid 10.5 until now are bit by these bugs. Bad choice Apple.