CDI burn issue (did 2 days of searching here)

[limeywarts]

Hello, DC newbie here. I searched through this forum for 2 days and still didn't find the exact info I need.

I bought a dc a few days ago and my friend gave me 3 backups to 'test' on my dreamcast... I managed to come home one day and I found someone had uploaded 2 new DC CDI's to my computer... those crazy hackers what will they do next.

Anyways my question is this.. I used diskjuggler to burn the images (one is self booting the other isn't) and neither work in my dreamcast with "cd image to cd drive". I tried both with the boot disk too. Is it that some backup games take quite a while to load, or perhaps did these sneaky software pirates upload a bad ISO to me?.... oh yea.. how do I execute an .sfv file to ##### the integrity of an ISO?

Please don't flame me, I was a burn victim already in a nasty automobile accident.