CPU Maximum Frequency

I am having a problem with performance in my dv2500t notebook. I'll be playing a game and all of a sudden I will have serious problems with framerate.

I did some snooping around and found that my CPU maximum frequency was dropping to 39%, then going back up to 100%, then dropping again. I thought I fixed by changing my power plan to high performance but that didn't actually fix it.

So I did some research online and found this forum that says it could be because my CPU fan is failing. Is this possible? What are the normal ranges for a notebook CPU under load and at rest?
http://www.tomshardware.com/forum/247629-28-suddenly-slow-full-speed

Here are the screenshots of Vista's resource monitor and the speedfan temperatures. I'm not completely sure but I believe the drops in temperature correspond to the drops in CPU frequency. It makes sense to me if it is a heat saving feature.

 

sounds like an overheating issue your cpu is downclocking to avoid damage.

 

What do you suggest I do? I already have it on a cooling pad. Someone told me I should try using a vacuum to clean out the vent. Is that a good idea?

Is the CPU fan failing a possibility or would there be more signs like a constant overheating issue?

 

Make sure all your vents are not blocked. You could try to clean it, but I bet the system is pretty new so it's probably not really dirty. Even though you have a cooling pad, is there enough air space around the laptop? Make sure you don't have it in a small space, and clear away everything around it on the desk.

You could also try to lift the laptop up and inch or so, by using some type of standoff under the feet of the laptop. The idea is to get more airflow under the system. If you have them, Legos are a good way to build a standoff like this.