Ok I got the great little 50mm 1.8mm Canon Lens and I love it. Some of my shots have been OUTSTANDING!!! But today it seems to be searching and searching and searching and not locking down..... (I`m shooting indoors in my sunroom, its an over cast day with no sun, but i`m 4 feet from a glass door, plenty of light) I just got it a few days ago. I`m wondering if i should send it back. its really getting to be a pain in the butt. I also can see LOTS of dust inside the lens... I`m shooting a doll (I sell on ebay for a living, work from home). I have a Canon 40d and I can select a focus point with my camera, I`m selecting hight points, dark points, flat places. I`m trying every thing. I`m moving the tripod all over the place. I keep getting the focusing searching with the lens. Then i put on my 28-135mm and its solid as a rock. But I want the sharpness of the 50mm 1.8. should i send the little bugger back, first because of all the crap inside, and second because of the searching? also what causes a lens to search. i`m sure its me, how can i help this little fellow. my big lens is having no problem at all. I don`t see the dust on my pics, i just wanted to add that. I also tried changing the focus points in my camera to other focus points thinking that maybe that was the problem but it didn`t matter. sometimes it locks on and when it does WOW.. NICE SHOT. so any advice?? I got it at B & H and while there is still time if i need to send it back.... well....if i have to i will.