I am having this problem as well. I've tried changing the oldest_article and max_articles_per_feed number. Currently it's only grabbing the first 10 in unread. Here is the error it gives me when it tries to grab any of the other articles beyond the first 10.
Code:
Why Is Illinois So Corrupt? from Unread articles
http://www.chicagomag.com/Chicago-Magazine/December-2010/Why-Is-Illinois-So-Corrupt-Local-Government-Experts-Explain/index.php?cparticle=1&siarticle=0#artanc
Traceback (most recent call last):
File "site-packages\calibre\utils\threadpool.py", line 95, in run
File "site-packages\calibre\web\feeds\news.py", line 839, in fetch_article
File "site-packages\calibre\web\feeds\news.py", line 835, in _fetch_article
Exception: Could not fetch article. Run with -vv to see the reason
I get this error dozens as times as it goes through all the articles.