For some reason I am just not able to find the Rasplex System Settings...
I know they were there, I know how the menu is supposed to (or at least used to) look, but I don't know where they went or when.
Under Preferences, I have the categories Appearance, Playback, System and Network. But nothing where I'd be able to configure my wireless network settings.
The OpenELEC 'System Settings' submenu is not found 'inside' the 'Preferences' menu (which is almost identical for PC PHT and RasPlex).
You should have the 'System Settings' entry at the same side menu level where you have 'Preferences', 'Control Precaching', 'Shutdown', etc.
It should be between 'Preferences' and 'Control Precaching', like this:

Am I missing something or is something wrong with my setup?
If the 'System Settings' entry is not present in your side menu, as shown above, even when you scroll through the entire menu, then something is FATALLY wrong with your install.
NB: This assumes that you are using the original 'Plex' skin. If you experiment with custom skins, then you must accept that some of those may lack menu entries specific to RasPlex or the OpenELEC system, since many of those skins were designed only for PC versions of PHT.
Hmmm: On second thought, I see that you have a 'Switch User' entry in the menu that must be specific to the new 'Plex Home' usage, meaning that your PMS server has multiple local user accounts defined. This is something I never have done and probably never will, since it radically modifies how the PMS server works. Apparently the inclusion of that entry in the menu has usurped the position normally reserved for 'System Settings'. I'm not really sure how to deal with that problem.
One thing you can try is to boot RasPlex with the network disconnected (just pull out the Ethernet cable and/or any WiFi dongle).
Since RasPlex then can't reach any server it should refrain from making any menu changes that depend on the server's 'Plex Home' usage.
Perhaps that will allow you to see the 'System Settings' entry. And then you can try reconnecting network after opening the 'System Settings' submenu.
Oh yeah, I'm running 0.5.1 on an RPi 2.
That shouldn't matter. RPi1 and RPi2 versions of RasPlex have identical side menus (as long as it's the same RasPlex version).
EDIT: I just can't seem to rotate the images... I hope that doesn't matter :)
Nah..., we can just tilt our heads to the left... :lol:
Best regards: dlanor