Only One Core Seen In Linux On Smp Platform

After doing a kernel update; 'uname -a Linux linux-798r 2.6.18.8-0.7-default #1 SMP Tue Oct 2 17:21:08 UTC 2007 x86_64 x86_64 x86_64 GNU/Linux', I noticed that my BOINC client is only utilizing one cpu to do computations. In gnome-system-monitor I only see one CPU, whereas before, there were two shown. I'm lost as to why all of a sudden I can't see both CPUs available in gnome-system-monitor.

I'm also experiencing difficulties in applying updates, getting 'Dependency Resolution Failed' errors left and right. Is there a way around this? How can I get my system to use both CPU cores?
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sm@linux-798r:~> cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 15
model : 43
model name : AMD Athlon™ 64 X2 Dual Core Processor 3800+
stepping : 1
cpu MHz : 2009.268
cache size : 512 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt lm 3dnowext 3dnow up pni lahf_lm cmp_legacy
bogomips : 4021.00
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp

Please do not hold me to this, I'm just going from (my rusty) memory . . .

I have the same cpu, except the 3600. When I built this machine I was using 10.2. I found I needed a newer kernel than the 2.6.18, so I added the 10.3 (then) Factory repository (now of course the 10.3 production repo) and 2.6.22 installed just fine and everything has been working perfectly. I stress tested the system extensively (the cpu is overclocked), all OK.

I upgraded to 10.3, and am still having the same problem:
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sm@linux-798r:~> grep -i core /proc/cpuinfo
model name : AMD Athlon™ 64 X2 Dual Core Processor 3800+
core id : 0
cpu cores : 1
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sm@linux-798r:~> uname -r
2.6.22.16-0.2-default
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Does anyone have any idea why the kernel is only seeing one core? I did a kernel upgrade today to 2.6.22.16 in hopes of the problem being fixed, but it's still here.

I'm showing this

model name : AMD Athlon™ 64 X2 Dual Core Processor 5200+
core id : 0
cpu cores : 2
model name : AMD Athlon™ 64 X2 Dual Core Processor 5200+
core id : 1
cpu cores : 2

see sig for spec

I'm showing this

model name : AMD Athlon™ 64 X2 Dual Core Processor 5200+
core id : 0
cpu cores : 2
model name : AMD Athlon™ 64 X2 Dual Core Processor 5200+
core id : 1
cpu cores : 2

see sig for spec
[/b]

I bought the CD from Ebay, full install with over 1000 packages, 2 CPUs, takes a long time, yes.
But it works out great. I did try CentOS 4, and I got the same only 1 of 2 CPUs issue.

This problem turned out to be due to a kernel bug, which was quickly patched. Somehow there was a bug in a kernel update which turned my dual core chip into a single core chip.