ok now tested on my core 2 duo laptop (also using x86_64). It works fine here too but I get a weird message on boot: [..] Intel(R) Core(TM)2 CPU T7400 @ 2.16GHz stepping 06 CPU 1: Syncing TSC to CPU 0. CPU 1: synchronized TSC with CPU 0 (last diff 0 cycles, maxerr 728 cycles) Brought up 2 CPUs testing NMI watchdog ... CPU#0: NMI appears to be stuck (59->64)! CPU#1: NMI appears to be stuck (27->32)! time.c: Using 14.318180 MHz WALL HPET GTOD HPET timer. time.c: Detected 2166.829 MHz processor. sizeof(vma)=176 bytes sizeof(page)=64 bytes sizeof(inode)=720 bytes sizeof(dentry)=224 bytes sizeof(ext3inode)=968 bytes sizeof(buffer_head)=104 bytes sizeof(skbuff)=240 bytes sizeof(task_struct)=1904 bytes Uhhuh. NMI received for unknown reason 2c. Do you have a strange power saving mode enabled? Dazed and confused, but trying to continue Uhhuh. NMI received for unknown reason 00. Do you have a strange power saving mode enabled? Dazed and confused, but trying to continue migration_cost=23 [...] what does this mean? I don't see it with 2.6.18 and I have not seen any problems because of it (yet)