Below are the known issues with PES. This includes both the PES Python GUI itself and the Raspberry Pi SD card image based on Arch Linux.
Issue #1: Raspberry Pi HDMI-CEC interference¶
Some models of Raspberry Pi when disconnected from the mains but still plugged into a HDMI-CEC enabled TV via HDMI can cause other HDMI-CEC devices not to receive HDMI-CEC commands. HDMI-CEC can be known by different names depending on the manufacturer. For example, Samsung refer to such devices as “Anynet+”. If the Raspberry Pi is powered off, but left plugged into the mains the issue will not occur. Alternatively, if you unplug the Raspberry Pi from the mains and then also unplug the HDMI cable from the Raspberry Pi the issue will not occur. Sadly, I have no control over this issue. For more information, please see: http://www.raspberrypi.org/forums/viewtopic.php?f=35&t=14273
The Raspberry Pi 2/3 does not suffer from this issue.