Photo issues

Hi all,

I have recently purchased a new Canon 5D, and have been having issues getting a clear crisp image.
I have called into a few training session's of AFL Footaball and below are a few images with the 5D and 1000D, comparing the two.

The photos that come out blurry have been taken with a Canon 5D, 70-200 II L and 2x extender attached.

I have tried all the different settings with no luck.

On the other hand my previous camera that I was using was the Canon 1000D which has produced far better quality (as seen below)

Any suggestions / tips / help would be more than appreciated.

Thanks in advanced.

Canon 5D MII , 70-200mm L II , 2x Extender

View: original size

Canon 5D MII , 70-200mm L II , 2x Extender

View: original size

Canon 5D MII , 70-200mm L II , 2x Extender

View: original size

Canon 1000D , EF-S 55-250mm

View: original size

Canon 1000D , EF-S 55-250mm

View: original size

Canon 1000D , EF-S 55-250mm