How long have the seeds been in the paper towel? I've noticed a musty smell after leaving duds in wet paper towels for over a week, and by the time I notice it, I trash 'em. If you've been trying to germinate for over a week, and they still haven't cracked, it's likely that they're not going to. If they haven't been in there for very long (day or two), then just replace the paper towel and maybe add a small amount of hydrogen peroxide to the water you use to wet it with. I highly doubt that it's the seeds causing the offending smell.

Also, don't know how you're doing it, but I like to keep the folded paper towel inside a ziplock bag... keeps it from drying out too quickly.

Take care. :jointsmile: