This is an article by Dave Hyde of Miami's Sun Sentinel concerning the perceived character issues of Ryan Mallett. It's very lengthy, but also very much worth a read.
Now I realize that this is essentially a fluff piece; there's not much proven info there. However, there really isn't much proven info on the other side either, and this is one of the only pieces that looks all the way back through every stage of Ryan Mallett's football career and tells the other side of the story.
Could he still have character concerns? Absolutely. But this is definitely worth taking into consideration.