I have a new PC with a 64 bit 6 core AMD processor and 8GB of memory. I have tried Mint, Suse and Fedora latest 64 bit versions, but in all of them after the OS has loaded the pointer is in the centre of the screen and will not move. I have tried several usb input devices (optical mouse, ball mouse and tracker ball) in different ports but none work. However, on a whim I tried the 32 bit versions of these OSes and all work just fine! What is the difference between the mouse drivers in the 64 bit and 32 bit versions? How can I get my pointer devices to work with the 64 bit versions. I have no problem with the keyboard. Is this the right forum for this Question?
I found the answer in the Ubuntu forums: In the Peripherals section of the BIOS set the IOMMU to enabled (the default is auto). Alternatively you can do something in the GRUB boot file to set the IOMMU. You will need to take this route if you are multi booting with an OS that requires the IOMMU to be disabled, but I am multibooting with 64 bit Linux distros, so I can just set it in the BIOS.
More details here http://www.cyberciti.biz/tips/howto-turn-on-linux-software-iommu-support.html