I know this is very old. But, related to the OP's actual question to rasplex devs: did they ever provide a way to 'reboot' rasplex? I have berryboot and rasplex all setup (thanks to you), and i don't see a way to reboot. Have to pull the power cord.
That's not how it should be done, and each time you do this you run a risk of corrupting the SD card contents.
In fact, if you've been doing this for some time now, then it's almost certain that your SD card is partially corrupted, which can have random effects.
The reason for the corruption is that all modern system software uses log files to keep track of activities, and the user has no way of knowing when such a file is being written. Unplugging the RPi while it writes to SD card is like unplugging any normal PC while writing to HDD. The results can be fatal for that operating system.
Since you see a need to do this at all, I must assume that you are not familiar with the "Plex Home Theater" program as used on PCs. (aka: PHT)
That's the program which RasPlex is based on, and except for a few additions, such as OpenELEC settings, it works identically.
PHT and RasPlex both use a side menu containing commands to access system and application preferences, and also to quit the program in various ways.
For the PC versions of PHT there are three exit options: Quit, Sleep, Shutdown.
For the RasPlex implementation of PHT there are two: Shutdown, Restart.
'Shutdown' will put the RPi in complete shutdown mode, after safely terminating all OS activity. New restart will need to be done by removing+applying power.
'Restart' will reboot the RPi from scratch, after safely terminating OS activity as above. With BerryBoot this means that you will reboot the BerryBoot menu.
I'm a bit surprised that you've been able to use RasPlex at all, without ever being able to configure it.
I say this because the PHT preferences menu and the OpenELEC settings menu are both reached through the same side menu as the exit commands.
But I suppose it would work anyway if your PMS server is in the same LAN and does not require local authorization for access.
The side menu is reached simply by pressing DPad-Left in the main menu (the startup screen), at which the normal menu entries (media sections etc) are replaced by the side menu commands. At this point you can either use one of these commands or press DPad-Right to go back to the normal main menu.
NB: The above assumes a rather 'newish' version of RasPlex, as very old versions of PHT and RasPlex had no side menu.
But you can't be using one of those versions anyway, as they should have 'Shutdown' command in the normal main menu.
Best regards: dlanor