Hmm, not sure what's wrong with you running out of mana all the time. My shaman is 62 and I've done quite a few BC instances and mana is never an issue. In fact, I am almost always at full mana and I put totems down at every fight.
Here's my armory:
http://www.wowarmory.com/character-s...odan&cn=Zevudu
What I do is keep earth shield on the tank at all times and that typically keeps them fully healed since it crits for 1.3k a lot. If he's getting a little low, I riptide. Other than that, I am normally sitting back watching health. I chain heal when the whole group gets hit and lesser healing wave people that aren't the tank most of the time.
I've been loving shaman healing in BC.
edit: After looking at your gear, I can see why you run out fast. A lot of your gear is enhancement. My Shaman was saving resto gear from the get-go and has a pretty good resto set (logged off in enhancement gear XD). I'd just be saving any piece you can for resto and you should see an improvement.