self-contained classrooms

Today Kelly Jewel and I were at a science conference that focused on how to integrate reading skills into science and vice versa. We talked a lot about ways to help our kids practice reading more by planning more activities that force them to communicate and read during science class, or use science topics to teach skills during your reading time. It created this internal struggle with me that I know lots of us deal with from time to time, but have never really had a "professional conversation" about how we all feel about it. I'm sure things are different for 6th graders, but as a 5th grade teacher I always wonder if teaming is best for my class. See, I was really encouraged today to find a way to put my GLE's together in a way that makes it really easy to plan units that allow students to inquire about lots of cross-curricular ideas. But then I start worrying about my 2nd section of science. I only get to teach Andrea's kids 200 minutes a week, so if I continue a science lesson during reading (while practicing reading skills), am I short-changing Andrea's class? Or if Andrea wants her kids to continue a S.S. lesson during writing, is my class missing out? Don't get me wrong, I LOVE teaming! It's so nice to know that I can trust Andrea to teach my class the S.S. GLE's, and I don't have to plan that, but I also wonder if I couldn't do more cross-curricular "stuff" with them if I kept my homeroom all day. It's really hard to think about giving up teaming; more than likely our kids are developmentally in need of changing classes, but what if.... What do you think?