So I just got Canon 40D and my Tamron 17-50mm f/2.8 yesterday. I was so pumped. Took a few pictures after the battery charged and put it down to read the manual for a while. Next time I use it, I'm trying to manual focus the lens and I can't get it to focus sharply. I do the best I can and take the picture even though the image in the view finder is kinda blurry. The picture comes out fine though. I didn't really notice this the when I first picked up the camera. I picked up my old 35mm to see if it was just me, but my 50mm lens on that focus tack sharp. I there's some sort of a adjustment I need to make? Is something up with the lens and I need to send it to Tamron?......