Solved
Only 1 CPU core on Dual core system.
Ubuntu 9.10 Karmic Koala was lagging. When I checked System>Administration>System Monitor It showed only 1 CPU. So I tried $ cat /proc/cpuinfo
same 1 CPU. So here is how I fixed it.

On my AMD x2 Dual core I to accesses my BIOS setup utility by holding down the Del key when starting my computer.

I used the arrow keys to highlight POWER and scrolled down to ACPI APIC SUPPORT and pressed enter to select Enabled.

Problem solved.

ACPI APIC SUPPORT was disabled by default.
I never needed to do this with other versions of Ubuntu.

Here is a link to another fix that I did not try due to Grub 2.
http://ubuntuforums.org/showthread.php?t=1144905