SLOW DOWN!!!
Assuming your material hasn't shifted and is binding the blade, you're pushing too hard and too fast. Even if your blade is dull, there is a speed at which you can cut the material and not cause the blade to bind up.
I've seen this with almost everyone I've ever lent a saw to... including some people who are actual, professional carpenters. Matter of fact, it's the only reason why I'm reluctant to lend my saws to people.
As for blades, more teeth does indeed make a smoother cut but, it also requires that you slow down even more, because if you blow through a piece of material with an expensive, thin kerf, 40 tooth blade you will cause the blade to warp and thus, bind up.
Here are some blades I use on my circular saw:
Shop DEWALT Precision Trim 7-1/4-in 60-Tooth Circular Saw Blade at Lowes.com
Shop CMT 10-in 80-Tooth Continuous Circular Saw Blade at Lowes.com
Oldham also makes good blades and I run a thick kerf one on my small table saw, for ripping. And while all of the above blades can and will cut faster and cleaner than the average saw blade, they can also all be pushed too hard through the material and the result will always be binding up of them at the least. At the worst, binding a saw blade can cause you and/or other people and structures around you some serious harm.
So again....slow down. ;-)