I reccomend Macromedia Flash MX, Swish 2.0, Swish Max, and Swift3D.
Flash MX is very powerful software to create a flash animation, but you need a little bit experience of programming.
Swish is easier to use but i dont think you can do as much with swish as you can with Flash MX.
This is just my opinion. Ive always used Flash MX and combine with Swish for this time.
Well I reccomend sothink flash tools, such as sothink swf quicker, swf decompiler, swf easy. They all work well on my computer, and i think they are more easier to use than adobe flash.