Lawns - Help - What is wrong with my Bermuda Lawn?

My lawn is about 50% brown with very little new grass growing. Front needs mowing every 7-10 days, back could go a month.

This is the 2nd year this has happened, I thought last year I was over watering because when the grass did not turn green in May/June I kept increasing the amount of water. This year, I just increased the water by the same amount as I did for the front, front yard is very green.
I keep up on the lawn with fertilizer every 6-8 weeks and my winter grass was absolutely beautiful.
I also have a weed problem, currently about 10% of the yard is covered, last year this quickly spread to nearly 100% of the lawn. See close up of the weed below.

I am stumped. :wall:

http://i685.photobucket.com/albums/vv215/lionsandwings/IMG00061-20090719-1342.jpg

Close up of the lawn...
http://i685.photobucket.com/albums/vv215/lionsandwings/IMG00062-20090719-1343.jpg

Close up of the weed...
http://i685.photobucket.com/albums/vv215/lionsandwings/IMG00063-20090719-1409.jpg

Have you taken soil samples all over, yet. You should get an analysis from your county extension service to determine what your soil may be lacking in nutrients. Sometimes it is as simple as liming the lawn. Certainly with weeds, you could use lime, but how much? The report should tell you. Watering alone is not always the answer, but what makes the grass grow.

I just got my soil test results back.
8.0 PH
0.53 Soluble Salt
48.2 Phosphorus
172 Potassium

The test recommended adding sulfur granules to lower the PH (20 lbs /1,000 sq feet).

I am going to go tomorrow and see if I can't find me some sulfur. Any other suggestions?

A good core aeration is usually near the top of my list.

I would try 2-4-d amine on the weeds because the weed is a broadleaf and the 2-4-d will only kill the weed not the grass since the weed is a broadleaf and the grass in not.