Kat-I am also among the few that uses the original cover - I just put two small round pieces of velcro on the back and it never comes out unless I want it to!! No more face injuries!!! Although I know I'll give in with the Oberon, those are too pretty to pass.
I, too, use the original cover. I read a tip on the forums to use the elastic on the original, and put it over the lower right hand corner, just barely catching the edge. I haven't had mine fall out (although I don't hold it over my head in bed, LOL!). I did just try holding it Kindle down and shaking it slightly; it didn't budge.
I'm saving up for an Oberon cover, I know it will be fantastic!
Betsy