Server showing HT CPU00 & CPU01 but one is not functioning

# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping : 9
cpu MHz : 2795.307
cache size : 512 KB
physical id : 0
siblings : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
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 cid
runqueue : 0

bogomips : 5583.66

processor : 1
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping : 9
cpu MHz : 2795.307
cache size : 512 KB
physical id : 0
siblings : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
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 cid
runqueue : 0

bogomips : 5583.66

21:36:30 up 1 day, 9:47, 1 user, load average: 7.74, 8.68, 10.72
484 processes: 479 sleeping, 4 running, 1 zombie, 0 stopped
CPU states: cpu user nice system irq softirq iowait idle
total 28.8% 8.4% 21.8% 0.0% 0.0% 0.0% 140.6%
cpu00 28.9% 8.4% 21.9% 0.0% 0.0% 0.0% 40.6%
cpu01 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0%