Odd Nautilus behavior

Nautilus just started misbehaving... it'd worked just fine prior to this. I've changed nothing on the machine.

I attempted to run Nautilus by double-clicking the icon on the desktop for my cell phone... the cursor clocked for about 15 seconds, but nothing else happened.

I opened Terminal, searched for all PIDs of Nautilus, and killed them all.

I scanned all the drives for errors. I did a SCRUB on the ZFS drives... no errors.

From Terminal, I issued nautilus... the terminal hung with no errors. I had to Ctrl-C out to get back to the command prompt.

I rebooted... no change. I checked that all of the dependencies for Nautilus were installed, they were.

I issued sudo nautilus, and Nautilus started right up, no problem.

I uninstalled and re-installed Nautilus-Admin, then attempted to start Nautilus from the command line... no change.

I uninstalled and re-installed Sushi, then attempted to start Nautilus from within Software Center... no change.

As I sat there pondering for five minutes, Nautilus popped up! It was working properly again. I closed it, and opened it again by double-clicking the icon on my desktop for my cell phone... it worked, opening nearly instantly.

Five minutes later, it's doing the same thing again!

And the whole while that Nautilus is doing this, I can access the drives from Thunar without problem.

Any ideas what could be causing this?

Have you checked system logs for anything in regards to a failed Shared Object (.so) file?
Have you checked the readahead package?
Have you checked tracker-miner-fs?

System logs are disabled except for boot logs.

I don't have the readahead nor the preload packages installed. In the past, I'd manually set drive read-ahead higher than default, but I found it increased latency too much for a small increase in data throughput... so it's at defaults for this install.

tracker-miner-fs is masked (because I couldn't purge it due to dependencies). It's been masked for awhile, and Nautilus worked just fine until today.

What gets me is that it runs just fine under sudo, but not otherwise... what would cause that? Root doesn't own anything under /home.

[EDIT]
Huh... now it's working again. For some reason, the icon for Thunar disappeared from the Zorin menu, so I'd had the Main Menu application open to set up the menu entry and a custom icon for Thunar, and Nautilus opened right up and worked properly to select the icon. After that, it started working ok again.

Perhaps an update was needed? My preferred file manager is Dolphin, but then again my preferred DE is Plasma (KDE).

This may be coincidental or it may be indicative that a configuration in your Home Directory (~/.confg) is interfering with Nautilus.
It does imply that it is not an issue with shared object files, though.

Oh, yes. I remember that thread.

You do follow a certain amount of system modifications...