I'm using Fedora 20.

When I click the system tray icon for Dropbox, it opens in a "Files" window, instead of Dolphin. I have changed the preferences in the Files window, but they return to default settings after reboot.

I would prefer to have Dropbox open in a regular Dolphin window, but if that's not possible, then having the Files window retain my preferences would be suitable. Thanks for any suggestions.

Can you please provide a screenshot of this Files window? It is likely either a GNOME application, or some integrated functionality provided by the Dropbox application itself.

The left click action of Dropbox tray icon (or 'Open Dropbox Folder' from it's context menu) calls the operating systems default file manager, passing it the location (normally ~/Dropbox) of the folder to display.
That is the case here, Dropbox 2.8.2, openSUSE 13.1 and KDE 4.13.

Perhaps check to see what the default file manager is set to ?

Thank you both. It appears to be Nautilus, built into the Fedora Dropbox build. I'll see if I can install a different Dropbox version.

As Dropbox likely follows GNOME/Gtk preferences, it may simply be a case of changing the default file manager GNOME applications use - to Dolphin instead.

Thanks for the suggestion. I've decided to leave it as is because as far as I can tell, Dolphin doesn't support sync status markers on the folder and file icons in Dropbox. I'm using the Nautilus window to quickly check sync status, and using my usual Dolphin shortcut for file management.