MacBook Internal Fan

Is there a thread discussing MacBook's batteries dying faster because of a fan that is continually on?

Within the last month, my one year old 2nd generation MacBook Core Duo 2ghz has started to have signigicantly less battery life, around 1.5 hours, and I attribute this problem to an internal fan that I can hear constantly running. I have tried many basic things, such as restarting, shutting down for a long time, running macjanitor, disk repair, removing the battery, etc.

Something is making the fan run constantly, which is most likely something hot inside the computer.

Any suggestions?

bump.

I also have a problem with my MacBook Intel Core Duo 1.83Ghz. The fan goes on as soon as I run a CD/DVD or when I run the software Fireworks. I'd like to get this thing solved too.