Thanks everyone! I am completely comfortable doing them on a low beam. I get a little nervous on a medium beam and pretty uncomfortable on a high beam, but I still do them on high because I know I can and I don't want to get a mental block. I definately don't jump as much on the high beam.
gymdog, I'm pretty sure my injuries were just flukes that now mess with my head. The first one was about a year ago; I was wobbling and knew I was going to fall so I jumped off and rolled my ankle. The second one, in October, happened when I stepped down a little crooked and I split the beam and hit my knee weird; I've partially dislocated it before so it twisted more easily. But I usually go straight; those were definately off days. I already do a lot of the drills you suggested and they seem to be helping (I used to land really heavy on my hands [which did cause wrist pain]; now they're better but still need to be lighter before my coach will let me work a 'real' series as opposed to bhs swing through cw).
The answer to your question is kinda confusing.

I'm a lefty, and I learned my beam bhs with my left hand in front of my right, both hands grabbing the beam and turned out a little (but sometimes my left hand turns inward and grabs the right side of the beam), so I had the same foot and hand infront. I don't know if you remember my whole series dilemma at the beginning of the summer, but my coach wanted me to switch the foot I step down with so the swing through cartwheel would be on my good leg, but I convinced her to let me try doing a bad leg cartwheel instead. Well, I can't do the bad leg cartwheel very well, so a few weeks ago she changed it back to stepping out with my bad leg in my handspring, which has made me more uncomfortable with the skill.

So now I do have the opposite hand and foot in front. 3 coaches have told me that they can't see a difference and that my series looks a lot better with the good leg cw, but I feel like I have no split stepping down and sometimes like I'm stepping down crooked. I also land heavier on my hands then I have been on the good leg but not as much as I used to, so I guess that's kinda good. I know I definately need more reps to get comfortable with the bad leg step out; it just doesn't help that I don't have much confidence in good leg step outs after almost 2 years of doing them on high.
Thanks again and any more suggestions you can give would be helpful!