Downloading a backed up file

I was downloading a file from my online backup.   It was just a very small word document (23kb).  It took almost 15 minutes to retreive this one file.  Does it always take this long to download 1 little file?

I've just started using Norton Backup but am rather discouraged at the amount of time it takes to do anything with this program.

How does subsequent backups work?   Does it only back up those files that are new or have been changed since the last backup?   I can't imagine my computer running a backup for 16 hours every day.