Do the original video files play OK on your PC/camcorder, before they're turned into ISO files?
If so, then try Sony discs again at 16x.
What are you using to make the orignal file(s) into ISO? I would suggest downloading the free ImgBurn and burning the ISO with that.
BTW, since you're getting replies here in your thread, you might want to edit your post, to remove your email address. This will prevent spambots getting hold of it. You have 30 minutes to do this I think.
EDIT: Since you can no longer edit your post, I've removed the email address for you.