HAHA!!! Oh, sorry. I had to laugh when I read your question. I have no idea wether or not bungee jumping would be more dangerous for someone with MS, but I would say it qualifies as an extreme sport (passtime??). I'm not saying you shouldn't do it, I just got a kick outta your question. Sometimes walking is more dangerous for MSer's.
Good luck to you, and remember, don't lie to the operator about your weight.