This very early macbook pro I salvaged (A1150) has two minor niggles.
Firstly, even though the keyboard seems to work fine this message appears at every boot 
Secondly, The mouse cursor acceleration is super sensitive despite setting it to its slowest setting.
Here is the about this computer
Hi @colinux 
About the error message, I think this is a miss-configuration between the x.org and your keyboard layout. I would try to force your keyboard layout once again + reboot to insure that correct values are set up. You can also search inside dconf-editor for a solution :
Try to set up your layout here :
Can be also the keyboard brightness of your macbook that is not supported, you can try playing this values to see if its changing something :
About the trackpad you can change its behavior here :
If you are talking about a external apple magic mouse (i have one too) im advising you this driver :
Good luck
