Can an author write in multiple genres?

As I was going through things the other day (notebooks, CDs, printed drafts from 5 computers ago, etc) I found some stories I wrote that I still like. Most of them are in the rough draft stage, but I'm not sure anyone would want to read them. I'm curious what you guys think when you start reading a book by an author you like (because hopefully you all like me) and it's not like the previous book(s) you've read by that author.

Do you feel let down because they changed things on you? Or is it okay? Should an author stick to one genre or can they have books in slightly different genres? Can I go from Alaskan Healing to characters who time travel? Or believe in reincarnation? Or what if they practice magick (and it really works)?

Am I going to annoy people if I write books with different elements (that some people don't believe in)? Or should I use a pen name for them? Because, yes, they will be written. However, I only have so many ideas for pen names, and I'm not sure that all of my ideas fit into any one category.


**To clarify, my story ideas will only be published as novels. Short stories scare the crap out of me. I ramble too much to have short stories. Even if I refer to it as a "story", I mean really really rough draft of a novel that needs to be expanded into a novel.