rabbits that don;t get along

Question
About a year ago I got a bunny, Peanut (sex  I don't know). Peanut is a very friendly, happy house bunny. She/He gets all the love/care/food and time out of cage, it could ever need. About six months later, I adopted in a  six year old rabbit, Smokey (Don't know sex either), from a family friend who did not have the time to take care of him/her properly. Smokey is much more independent and shy about coming to people, than Peanut. At the begining I tried to introduce them to each other in a relatively neutral area, with access to each others cage. It all went to HELL, they just ran around and at one point they both ended up in Smokey's cage and fought (no injurys). Since then I let Smokey out first, let him/her relax, then let Peanut out. Smokey rans straight into his/her cage. Is there anything that I can do better? Should I get them fixed? Is it because they are the same sex? which I don't know because neither of them will stay flipped long enough for me to know. Also, Peanut has begun to try to hump mine and my boyfriends ankles, and not use the litter box that is outside of her cage all the time. I just need alot of help. I have let this go on for too long.

Answer
The first step in this is to get both of them sexed.  If they aren't cooperative in letting you take a peak, then let a vet do it.  This would also save you time because you can schedule the spay/neuters right them and there.

One of the things that make bonding a lot easier is to have them fixed.  The hormones really get in the way of things.  

The behavior you see with Peanut makes it sound like Peanut is a male.  Not using the litterbox is a territorial issue.  Peanut is marking territory.  Unfortunately, if Peanut is a boy, you may see spraying next.  And that is something quite unpleasant.  A quick snip will take care of the humping. The neuter, along with Peanut and Smokey working things out, should make the litterbox habits better.

Right now, there isn't going to be much you can do to get them to get along.  The first step is to get Peanut fixed.  And if Smokey is healthy enough, it might be helpful for Smokey to be fixed as well.
About a month after getting fixed, you can try working with them again.  

Go slow, you can try putting their cages next to each other.  Or switch items from the cages so they can get smell each other's scent on things.  Or even put Smokey in Peanut's cage and vice versa.  Then you can try the neutral room approach and see how it goes.

This site has some beginning tips on bonding:
http://www.rabbit.org/faq/sections/introductions.html

And if the going stays tough, this site is a real good guide on bonding including when things just don't work out.

http://www.rabbitnetwork.org/articles/bond.shtml

This may take awhile.  And be aware, it possible it might never work out.  None of the rabbits I have currently like each other, and they are quite violent about it.  Sometimes it just doesn't happen.  But keep trying, once they get the hormones gone, things might calm down enough for them to be friends.