Fascinating issue and the rest of the Retraction Watch website is eye opening!

I rarely read academic journals anymore but I had always assumed the top journals did a good job of filtering out bad papers and quickly retracting those that were later disproven. Like every human activity it is not so simple.

http://retractionwatch.wordpress.com/

Edit: Warning this is blog addictive - I just spent a solid hour reading. It's kinda science gossip but still important.