System hangs when copying large quantity of files from external HD

Question

A little background:
I was having some problems with the original OS (10.4.1), including periodic freezes. I bought the Mac Box Set '09 and installed Snow Leopard (10.6.5), but ran into some problems and in the process had to reformat my internal hard drive. I backed up all of my photos (~16GB), Documents (~1.5GB) and Music (~50GB) on a WD external hard drive (My Passport 750GB).
*The problem*: After the 10.6.5 install, the computer works great (no random freezing when I click around in Finder), but I am having trouble copying files back to the internal HD from the external. I can copy up to about 1GB at a time without any problems, but any time I try to copy more than that, the system hangs (first the spinning disk cursor, then it totally freezes) and I have to do a hard reset. I have tried copying a number of different folders (pictures and music), and the same holds true: small folders with a few files copy without a hitch, but any time I try to copy a lot of files at once: freeze city. This problem occurs whether I am using Finder to copy the files or iPhoto/iTunes to import them.
I have verified both disks using the Disk Utility AND restructured/verified them using DiskWarrior. I also had no problem copying all of my files from My Passport to a second external HD using this MacBook, so I assume the Passport is fine. Is this a physical problem with my internal HD? If so, why can't DiskWarrior or DiskUtility catch it? I just noticed that there is an internal HD recall for this model of macbook, although I have never gotten the question mark on startup that would qualify me for a replacement HD from Apple. Maybe it's a problem with Snow Leopard... I would love to know if anyone has had this problem before or has some advice.
Thanks,
Sam

Answer 1

External USB/FW drives 'falling off' or drives spinning down (going to sleep) and I would assume since you have been running 10.4 that the Passport might be older model, perhaps not the latest firmware, maybe not compatible with Macs and with Snow Leopard.
Obviously you want FW800 but for some, USB worked where FW fails.
Hard Reset: do you have another hard drive to boot from to run Disk Warrior? is that updated to 4.2 or later? you never want to run DW from CD. Else, boot from OS X 10.6.5; or Single User and run FSCK. HFS+ doesn't take kindly to hard restarts even though a Safe Boot helps a little, that isn't as good as FSCK or one of the other options.
Disk Warrior Rebuild is more thorough, but if you hold OPTION while clicking on REBUILD it brings up more choices. And you want to scan the full hard drive.
Going back to Aug/Sept 2009, there were a lot of threads about external hard drive issues. Wish I could point to a good one.