What should I do about my arguing friends?

I have 2 friends that are arguing and I really don't know what to do about it. Lets call them Betty and Jane for now. Betty and Jane have been friends since kindergarden, but they are arguing now. I only met Betty and Jane this year. I was friends with Betty before I was friends with Jane. Betty is really dramatic and loves acting. With her I can laugh my head off for hours on end. Jane, on the other is logical but can still make me laugh. I would laugh with Betty more than with Jane, but I think I would be able to tell my secrets to Jane easier than I would to Betty. I have already made it clear to my friends that I don't want to be sucked into their argument and I don't want to take sides because I don't want to lose my friends. I think Jane was mad at Betty before Betty even knew it. (Sorry for the bad names, cont in details)