Welcome to Apple Support Communities
OS X moves unsupported apps and extensions automatically to a special folder and disables them. If not, you will start seeing kernel panics and your Mac Pro wouldn't work correctly.
If your LaCie devices are working properly, there's nothing to worry. If not, download the most recent version from the LaCie site > http://www.lacie.com/us/support/drivers/driver.htm?id=10239