Linux – Why /proc/cpuinfo shows different flags for cores on the same cpu

cat /proc/cpuinfo on my system gives me different flags for my 2 cores. Can someone explains to me why? I'm running Ubuntu 10.10 kernel 2.6.35-24-generic.

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 23
model name      : Intel(R) Core(TM)2 CPU         E8400  @ 3.00GHz
stepping        : 10
cpu MHz         : 2999.820
cache size      : 6144 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 2
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni monitor tm2 ssse3 lahf_lm dts
bogomips        : 5999.64
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 23
model name      : Intel(R) Core(TM)2 CPU         E8400  @ 3.00GHz
stepping        : 10
cpu MHz         : 2999.820
cache size      : 6144 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
apicid          : 1
initial apicid  : 1
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 xsave lahf_lm dts tpr_shadow vnmi flexpriority
bogomips        : 6000.04
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

I noticed this problem when trying to configure my system for KVM. I'm unable to load the kvm_intel module and I have no other clue why this is so. One of the cpu flags shows me that I support vmx but not the other.

Thanks