F15: Second monitor not detected after booting finishes

[Steven F. LeBrun]

When Fedora 15 [x86_64] is booting on my laptop, it starts on the laptop 
screen, then it throws the startup splash screen on my second monitor.  
When it finishes booting, it no longer can detect the second monitor.

Why can Fedora 15 see both monitors, laptop screen and external monitor, 
during the boot process then when finished booting can no longer detect 
second external monitor.  Is this a problem with the kernel, modules, 
drivers, desktop, hardware?

I have tried connecting the external monitor directly to the laptop with 
an HDMI connector and through an USB Docking Station using DVI.

OS:             Fedora 15 x86_64
Kernel:        2.6.38-35.fc15.x86_64
Desktop:    Gnome 3.0.1
System:      Dell XPS 15R (i5-2410M CPU @ 2.30GHz x 4)
Graphics:    Intel Sandybridge Mobile
Memory:     8 GB


-- 
   Steven F. LeBrun

Quote: /"The objection to fairy stories is that they tell children there 
are dragons. But children have always known there are dragons. Fairy 
stories tell children that dragons can be killed."/
      -- G.K. Chesterton