Additional relevant data: We have a couple of ls21 boxes that are able to boot kernel -100 fine, and the main difference between these boxes and the one that is unable to boot -100 is that the failing box has SAN disks. The -101 kernel david mentioned has a patch from jvrao@ibm that was supposed to fix a long boot (20-30min) issue he observed when booting from SAN.
Created attachment 330366 [details] Output of lspci -v
Created attachment 330367 [details] lspci -v from ls21-1.farm.hsv.redhat.com This is the 'lspci -v' output from ls21-1.farm.hsv.redhat.com. This system successfully boots and runs MRG RT kernels including 2.6.24.7-100.
*** This bug has been marked as a duplicate of bug 485428 ***