I had a similar problem with the local UPN affiliate not broadcasting the HD signal of Enterprise for a couple weeks. I emailed them and later got a response from the Program Director that they were unaware that the HD signal wasnt going out that found several issues they were also unaware of. By the next week they had it fixed, and it's been in HD ever since.
Luckily I haven't had any problems w/ the FOX broadcasts (NASCAR looks nice in widescreen!)
I just received an e-mail from my FOX station and they said that they are not broadcasting the widescreen feed yet. He informed me that FOX is going to switch over to 720p in "a couple of months" and they are waiting for that before the do any widescreen. Thanks for the advice!
I live in Las Cruces and get the same Fox channel you get. (I assume you are getting it OTA as I am) They actually have two channels, 15-1 and 15-2. 15-1 is the network feed and 15-2 is the local. 15-1 seldom broadcasts anything, usually at night if they do. 15-2 does not do wide screen yet but the picture quality is really good. I emailed KFOX a while back asking them about HD content (like when they would actually do it) but did not get an answer back from them.