There is a GUI-like application called htop which is pretty decent. (GUI-like here means that it runs in a terminal, but allows you to use the mouse on a PC, so I assume you can use the stylus on Maemo. I don't own a Maemo device yet unfortunately ) It allows you to see what process uses most of the CPU time and memory and kill them. However Flandry is right in saying that you should be careful and not be killing arbitrary processes.

I don't know how your system setup does it but that's the way it seems to work on my kubuntu box and a 1 minute google of npviewer.bin suggests that is indeed the way it should work.

Maybe you installed a different flash implementation?

This is not really on topic for a Maemo thread so that's all i'm going to say about it.

not only flash games even if you install new apps especially from devel-repository