I made a gist of the problem here:

https://gist.github.com/1430906

I create a new object like:
a = Root.new

Then I save it.. and run a method on, in particular the method '.upvote' from the mongoid_vote gem...

Then when I try and create new instances like
b = Root.new
one of the values from "a" is persisting.....

I'm not sure if this is a bug with Mongoid or something that the mongoid_vote gem is doing.. but I don't know think its doing anything that would alter how new objects come out... Let me know if I can get more information but the gist has a complete rundown...