My Dell Precision Workstation 670 crashes on Red Hat Enterprise Linux 6.0. How can I prevent this from happening?

Issue

• My system always crashes after starting for a while. Here is the message:

  Mar 31 16:14:53 server kernel: WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing 64MB of RAM.
  Mar 31 16:14:53 server kernel: ------------[ cut here ]------------
  Mar 31 16:14:53 server kernel: WARNING: at 
  arch/x86/kernel/cpu/mtrr/cleanup.c:1092 
  mtrr_trim_uncached_memory+0x2de/0x309() (Not tainted)
  Mar 31 16:14:53 server kernel: Hardware name: Precision WorkStation 670    
  Mar 31 16:14:53 server kernel: Modules linked in:
  Mar 31 16:14:53 server kernel: Pid: 0, comm: swapper Not tainted 2.6.32-71.el6.x86_64 #1
  Mar 31 16:14:53 server kernel: Call Trace:
  Mar 31 16:14:53 server kernel: [<ffffffff8106b857>] warn_slowpath_common+0x87/0xc0
  Mar 31 16:14:53 server kernel: [<ffffffff8106b8aa>] warn_slowpath_null+0x1a/0x20
  Mar 31 16:14:53 server kernel: [<ffffffff818cca5f>] mtrr_trim_uncached_memory+0x2de/0x309
  Mar 31 16:14:53 server kernel: [<ffffffff818c7121>] setup_arch+0x4c4/0xa9e
  Mar 31 16:14:53 server kernel: [<ffffffff814c7c23>] ? printk+0x41/0x46
  Mar 31 16:14:53 server kernel: [<ffffffff818c1b96>] start_kernel+0xdc/0x41f
  Mar 31 16:14:53 server kernel: [<ffffffff818c133a>] x86_64_start_reservations+0x125/0x129
  Mar 31 16:14:53 server kernel: [<ffffffff818c1438>] x86_64_start_kernel+0xfa/0x109
  Mar 31 16:14:53 server kernel: ---[ end trace a7919e7f17c0a725 ]---