A couple months ago, reddit started refusing requests from my web scraper. Figured out they started checking the user agent and refusing connections that didn't look like they came from a user's browser. Unless I missed an announcement somewhere, it doesn't seem like they're overly friendly about allowing web scrapers.
They are fine with it as long as you abide to their terms, they have a subreddit dedicated to reddit development and the reddit api which has discussion of scraping: http://www.reddit.com/r/redditdev
