jjmac, your question about mounting was right on. Using #mount got me on track: I didn't realize that I needed not just to access the partition through /mnt/hdd1 but also needed to issue the #mount /dev/hdd1 command. I've now changed my fstab to auto mount, and all works well. Thanks!

I think before I changed this, the files were being written to the /mnt/hdd1 DIRECTORY in a different partition rather than to /dev/hdd1!!! (Idiotic, I know! But I'm a PHP developer finally getting around to running my own server, handicapped by a Window$ background.)