I had a frustrating few hours yesterday. I put a fading rotation of images on a homepage, tested it thoroughly on my dev site and then once happy uploaded to the live site. Disaster! The images had looked like they white noise in them while they were fading. I had to roll back instantly, thankfully that was all of 60 seconds!
This caused a lot of head scratching, I tried many different images. It seemed to be only the images that were on the live site that caused the trouble, a real headache. I tried everything even taking screen prints of them an re-cutting in case of file corruption. I finally came to the conclusion that it was the black that was at fault, all three pictures had a large amount of black. Having found that out, I lightened the images by a small amount so there was no pure black in the image and all was fine!
Searching for similar occurrences, I did find a few references including this one http://social.msdn.microsoft.com/Forums/en-US/iewebdevelopment/thread/4df69380-c1ef-4fb6-8e7b-f133131b4abe
It does seem that Internet Explorer (6 through 8 at least) cannot handle pure black (#000000) pixels in Jpegs with a transparency applied without putting white speckles in their place, terrible!
