Both wget and curl have let me down. After my download aborted for some reason (after downloading more than 400 MB), wget refused to continue the download even though I had specified the --continue option. I then decided to try curl (curl has an option of continuing from a specified offset); but it turned out that for some reason, curl didn't stop at the point where it should have reached the end the file and continued happily downloading. End result: a total of about 800 MB downloaded, and still no ISO file. Grrr...