I've got a 27" Asus as my primary display, and a 22" Acer as my secondary.
For my PC, I use the DVI ports on each monitor. I wanted to hook my PS3 up to the Asus, so I grabbed my HDMI cable and did just that. Leaving my PC on, I turned on the PS3 and changed the primary monitor's input to HDMI. It swaps over to the PS3 and I can also see my secondary display, which is perfect.
But then when I shut off the console, my monitor's menu does not come back up so I cannot switch the input again. Only way to fix it is to unplug the HDMI cable and reboot my PC. This is a royal pain in the butt to do so, as my DVI cable from my PC to the monitor is just barely long enough between my desk and where the PC sits, so I have to unplug that to get the monitor out to fidget with the ports on the back.
I have no idea where to begin to determine if this is a problem with the cables, the monitor itself, Windows running in the background or even what to tag this with really. Any ideas?