this is a description of what i did to fix my error with starting undev on my linux centos box 
my server crashed today, when i logged in to my terminal video, it shows my server rebooting over and over. finally i see it load the BIOS then it starts GRUB then it start the kernal. then it crashes when it says:
welcome to centos release 5.5 (final)
Press 'I' to enter interactive startup
Setting clock (utc) Tue Jul 5 13:20:25 PDT 2011 [OK]
then it restarts again...
this is what i tried doing
when GRUB was loading i edit the kernal command and added
it worked, i booted, but then it crashed again, if should have updated my ntp server with the command:
yum update ntp
but i didnt. so next i tried another command:
quit splash acpi=off noapic
it worked but it failed at discovering new hardware..
finally i what i had to do is remove the power from the server for atleast 15 seconds then started the server. it worked, no more errors