First of all if this has already been addressed - forgive the redundancy. But all searches I did came up negative.
Second, this post is for anyone (like me) who owns an S1 series TV and also has an Oppo BDP-93 Blu Ray player hooked up directly to the TV via HDMI from the Oppo's HDMI 1 primary output.
Not long after I bought my BDP-93 - I became aware of a commonly known issue with Panasonic Plasma TV's in the S1 series.
The issue is that if you boot up the TV and the player and the TV has to switch to the input that your HDMI 1 output from the 93 is hooked to you get a red screen on the TV that can only be fixed by switching inputs on the TV and going back to the correct input. (this was only if you were going directly to your TV from the Oppo primary output 1 and not through a preamp or receiver)
This was apparently due to the fact that the Panasonics were booting up into "PC" mode rather than straight video mode. However, I've discovered that it may be a different reason. Read on!!
There was no fix on the Oppo or Panasonic side (or one that could be found) so those of us who had the issue just had to live with it.
Anyway, I think I have found a solution....
I was re-calibrating my TV using Disney's new WOW (World of Wonder) calibration disc. In the section that deals with overscanning. I learned that if the Panasonic TV's are set to "Size 1" in the "HD Size" setting of the "Advanced Picture" section, the TV is overscanning by about 5%. This was helpful if you could see SMPTE coding bars at the top of your screen on some broadcast channels.
However, I learned that if you chose to overscan - the picture was no longer transferring the source at a 1:1 pixel rate - it was, in fact, scaling the picture! And dropping the quality. (significantly)
So if you switch the "HD Size" to number "2" size/setting it turns off the scaling and you get a true 1:1 pixel transfer... and best of all: You no longer get the red screen requiring an input switch!
Anyway, I don't know if someone has already figured this out - but in case no one has I thought I'd pass this tip along for anyone else that is/was dealing with this issue.
Hope this is helpful.