Here's my guess about Fox here in Salt Lake with the wide bars. They are receiving the network signal in a compressed format, that is meant to be displayed as 16::9 480p, at the local station they run it though a machine that stretches it out and then pass it along to us.
It is a similar picture to having a anamorphic Dvd, which is then unsqueezed before it's displayed.
I further quess( and it's only that) someone is not manning a machine that needs to be triggered, or they are working on equipment that has to do with going HD, instead of 16:9 480p.
We used to have a Fox engineer here as well as Ken, maybe he'll drop by and let us know.
I don't watch much Fox programming, but I did tune into NASCAR, the past 2 races and it was the squeezed programs both times. Somebody that watches more regularly, say prime time evenings, where some of the programs are in 16:9 can chime in and let us know if those shows are being displayed the way they should. If it's only happening on the weekends, then I would speculate it's a problem with somebody forgetting to do something. It it is happening on all the shows Fox broadcasts in 16:9, then it's a hardware or upgrade issue.
As far as KSL is concerned, they strech and zoom on 5-2, instead of just showing a 4:3 picture with black bars. Personally I would rather them show 4:3 programming as 4:3, that way it I want it streched I can set up my TV or HDTV tuner to do it, if I want to watch it with bars I can do that as well.
There are a few shows which KSL does deliver in HD, and when they do it will not be zoomed and streched, that occurs on SD programming, or on a KSL edited program, such as Las Vegas, which NBC produces and sends to affiliates in HDTV, but with it's risque content, KSL edits and deletes scenes, which they can only do in SD.