ATI Rage+xawtv Solution
This is an answer as opposed to a question. After struggling with the problem myself (twice), I decided that it might solve some others' same issues.
I have an ATI Rage 64+ PCI tuner card and like to watch TV in Linux, because there are no Windows drivers for >98. I also have an ATI AGP card that allows me to use larger resolutions, that I use a majority of the time. A year ago I had TV working just fine, but it refused to work tonight. The only things that were changed from last time were the XF86Config-4 file, and the GATOS drivers had been overwritten.
I promptly replaced the GATOS files, from their website. This still yielded a blank xawtv with no sound. Changing channels, unplugging cable, etc. produced no change in this. Using Ctrl-Alt-Plus or Minus did nothing, besides change the screen, of course.
The device video0 did not exist, and this worried me. Video4Linux support was built into the kernel, and I recompiled with it as a module. This produced no change in the output of v4l-conf. I decided, however, that both avview and xawtv did not need video4linux because they can use xvideo instead. But I am still not entirely clear on this.
I was stuck with a blank avview and xawtv, each with no sound or static. I remembered from before that upon using a viewer besides xawtv (may have been avview, or may not), a memory error had occured causing the TV to not function. Apparently, and not surprisingly, the ATI card requires memory besides that on the screen to store the video information for the television display. xawtv gave no error message whatsoever for this problem. My card can have at least a 1152x864 virtual screen, and I was using that at the time. I reduced it to 1024x768 in XF86Config-4, and the TV worked immediately and flawlessly!
Nowhere in my search for answers did I find this memory issue mentioned. Maybe I just like nursing old hardware...? I hope this helps someone!