Battery life decreased after upgraded to Lion Has anyone noticed any battery life decrease after upgrading to Lion?

I'm on MacBook Pro (mid-2010). Before, on Snow Leopard, when unplugged I had minimum 5hrs of life. Now, it's not much above 4hrs at best. Is this a common problem?

I notice the estimate battery life now fluctuates a lot more than before, too.



UPDATE

Battery life is definitely lower than before upgrading. I'm getting up to about 5hrs of work now while I was able to pull out 6-7 before.

Re RAM usage. I'm not a heavy RAM user tbh. I always have at least 0.5GB RAM completely free and most of the time it's around 1GB free at least so this can't be it.
Rather than looking at the estimated time remaining, use your machine to determine if there is an actual difference or if it's just a change in the battery-life-remaining algorithm