My CPU is 64 bit, I have a PS/2 keyboard and a PS/2 mouse and I have tried Live CDs of Ubuntu, Kubuntu, Fedora, Arch Linux, Wubi installations, 32 and 64 bit (my CPU is 64 bit) and Puppy Linux. I am able to navigate between the menu options when there is one, but when I boot, the keyboard and mouse stop responding. Puppy Linux booted completely, but the keyboard and mouse didn't respond. Besides, pressing NumLock, CapsLock does nothing.
Note that Windows doesn't have this problem.
My keyboard and mouse work flawlessly in Puppy Linux 3.01, but don't in 4.x.
IMPORTANT: I can confirm that keyboard and mouse work in Ubuntu 8.04.4 LTS with linux 2.6.22-14-generic, but DON'T with 2.6.24-29-generic.