Canon 17-40mm L f4 focusing problem!

I have recently experienced and learned that the Canon 17-40mm L f4 lens has a focusing problem on its wide end. It seems that on a Canon 10D or similar sensor size, the lens will not focus correct if you use it around 17mm. If you try it out and look closely at the focus ring you will see that it moves slightly beyond the infinite mark (the 8 sign on its sign). This effectively mean that if you shoot at f4 nothing will be sharp in the picture. I dont know, but I regard this as a major bug in the 17-40mm (or a combination of the lens/camera).

Fortunately there is a workaround. The 17-40mm is parfocal, which means that its focus remains at the same spot even if you zoom after focusing. This means that you can zoom in (40mm), press the shutter half way to focus, and while holding the button down, zoom out to 17mm again and press the shutter to shoot. This has worked for me, and will show the true capabilities of this lens. So if you feel your images are soft at 17mm, its most probably a focusing problem. If you shoot at higher f stops than f4 it will be less visible though. The best thing is to adjust the focus manually if you are rigging up for a landscape shot. That way you have full control and can get everything from that little flower in the front to the mountain in the back in focus.

I hope Canon knows about this problem and maybe come up with a fix? It might even be solved by a software fix for the 10D maybe? Well who knows...