Straight from the Lenovo website:
"Newer model ThinkPads support a function to swap the key functions in BIOS. If you have a T410, T510, X201, W510, W701 or later ThinkPad, and wish to remap these two keys, check your BIOS for a setting.
F1 to enter BIOS on startup
Select Keyboard and Mouse
Toggle the Fn and Ctrl Key Swap enable or disable (normal)