Go to disk utility, there you will see a list of drives, click on the top level of your lacie and see what it says on the right. If it is an NTFS formatted drive it will not take files larger than 2GB. which is why it would stop at 8mins every time.
You can also format your drive from here (choose Mac OSX extended (journaled)) but note that it will wipe everything that is on the drive.
Hope that helps!
Thoren