When I try to merge images for HDR in photoshop, it almost always freezes up and stops responding. Any ideas why? I am running Intel Core Duo 2.54ghz with 4GB of RAM. Windows Vista 32-bit. I tried once with only 3 exposures being blended and it worked, but most cases ( even with only 3 pictures ) it freezes. It will open the pics as layers, but then freezes during Alignment.