Here are two pretty good in depth analysis of some opinons on what is ailing our defense and recommendations how to fix it, in case you hadn't read them yet.
http://blogs.chron.com/fanblogtexans...the_texan.html
and more on defense, and some optimism for the rest of the year at( me being an optimist as well, I always appreciate seeing more of that)
http://www.texansbullblog.com/
pretty much like everyone is saying, get more aggressive on defense, blitz more, perhaps let Kareem sit and learn a while.