With hampton beta1, Monitor Detection does not seem to work in either GUI or TUI installer modes. I've tried a MGA G400 + NEC MultiSync C500 and MGA G200 + AOC Spectrum 7 GLR, and neither were detected. RH 7.x does detect those monitors, if I remember correctly.
This is a kudzu issue.
If it helps any, this broke for the AOC Spectrum 7GLR during the 7.2 beta cycle. The NEC worked on 7.2. Full details of the AOC breakage are in #52092 which was closes as won't fix since it was so late in the release cycle....
What happens if you run (as root) 'kudzu -p -b ddc' after install?
Here's the AOC - MGA G200 combo: # kudzu -p -b ddc - class: VIDEO bus: DDC detached: 0 driver: unknown desc: "Matrox MGA-G200" mem: 8192
More monitor detection issues: a ViewSonic E790B (which RH 7.2 detects correctly, and which is in the monitor db) is detected as "DDC Probed Monitor - E7916"
*** This bug has been marked as a duplicate of 59556 ***