AI Servo very slow with a L lens

[lddw]

Hello,

I have tried to use AI Servo with my new 35L and I was very disappointed.
Today, I wanted to take a picture of a small girl and she was walking slowly. For these shots, I needed the burst mode of the 40d and I used the center focus point. The result ? ALL of my 40 pictures taken during several burst were unsharp.
This was not a motion blur but really an incorrect AF.

It was a sunny day and the AF was made not on an uniform surface

[Goshawk]

Was there good contrast on the little girl?(not sure if that is what you meant with not a uniformed surface)
I presume you made sure your lens was on auto.
I have no experience using AI servo with a wide angle lens but cannot think that it should make a difference.

[chauncey]

You don't give us much to work with...your settings, distance from subject, focus point, etc.

Might be that you'll have to check the focusing ability of the lens using tripod, MLU, remote shutter. Do this prior to warranty being over.

[lddw]

I still have one year waranty.
There is no focus problem with this lens in One Shot mode. The subject distance was 2m. I'll post you the picture when I'll be at home tomorrow.