I don't know the first thing about the 500 (wish I did) but if you have a camera USB file transfer port that can be hooked up to your laptop try doing a straight file copy from the camera to your external LaCie. If your LaCie rugged is like mine you've probably got FW800 and are using that from the laptop. See if the laptop's estimated copy time is less than 3 hrs. It should be far less, because a simple USB connection copying to a SATA internal drive is about 28 min. for 64 Gbytes. Don't expect that kind of transfer tiime going from USB to FW800 but it shouldn't even be close to 3 hrs.
If this setup I've recommended you try is faster, then it's just a process of elimination as to where the restriction is within your regular file transfer routine.
- Don
Don Greening
A Vancouver Video Production Company
Reeltime Videoworks
http://www.reeltimevideoworks.com