This one really has me scratching my head.

All was going along swimmingly until today. For reasons unknown to me the output from my PC is now squeezed into a 4:3 window. I get full height images, but black pillar boxing at the sides. The image actually looks squeezed. Pop up windows are extra slim and tall now.

As far as I know I changed nothing. I'm still set at 1920x1080 from my PC, I've double and triple checked my "format" setting on my TV, toggling through all the settings. "FULL" is the native 1:1 setting on my TV and the setting which until a few hours ago worked properly.

One thing that I thought may have caused trouble was I downloaded my free "digital copy" of The Blues Brothers using the code that came with the blu-ray I bought. When doing this I was prompted to install some add-on to windows media player to playback HDCP content. Thinking this may have caused trouble, I did a system restore back a couple days. No dice. I'm still squeezed into 4:3.

One other (likely related) issue. OSD from my receiver isn't working. I tried checking my setup settings on my reciever to see if something had been duped into thinking I had a 4:3 tv and the onscreen display has stopped working. When I press "setup" on my remote I hear the receiver click over and my screen goes black, but no onscreen display for setup features comes up. When I exit setup, it clicks back and I get picture again.

Weird. Any ideas?

I think my Onkyo (or it's owner) is whacked.