I took 2 sets of photos today at an old run down gas station and was planning on turning these into an HDR image. I'm using a Pentax K-x and the camera has a multi exposure feature that I used for the first set which I set to take 5 photos. This would have worked great except that the clouds in the sky moved a lot in the small amount of time that it took me to press the shutter all 5 times. Then for the 2nd set I did 3 shots with -/+ 2 EV. This didn't take nearly as long as the first set. After I got home I tried to put these 2 sets into both Photomatrix and CS3 and on both of them the images were blurry and not lined up at all. I'm guessing this was because the clouds. Is there any way to prevent this from happening again?