corrupt images

Hi all. I've been struggling with getting images to upload cleanly. I'm using php 4.2.2. When I look at the uploaded file info, it gives me no errors and the file size is fine. But the picture is all messed up. I'm using the move_uploaded_file function. The max size is 8mb in php.ini, and I set the MAX_FILE_SIZE in the form to 100k. None of the images I'm testing have been over 30k. I've seen that some people have had this problem, but a solution hasn't been consistent. Some said to use copy() and some said it's a bug in PHP. If anyone knows what's going on I'd appreciate some advice. Thanks! -jason