I have a client that claims that the same Flash animation plays faster on one computer and slower on other. Well the only thing I can think about it's that one computer is faster then other or internet connection speed is different.
You're correct. Both factors contribute to the speed of the flash animation, unless you're preloading the movie, in which case the speed of the computer (processor, available memory, etc.) would be the major factor.
Besides computer speed and internet connection, the Flash Player version is another big factor. Flash 8 Player is definitely faster than Flash Player 7, and newly released Flash Player 9 is even faster.
Flash 'speed' is totally dependant on processor, that's for sure. Also, the physical size of an animation can affect the playback due to screen refresh rate (if it's full-screen for example, it will run much slower). Flash player versions do seem to be getting quicker, but I suspect if you're creating work for commercial use, be careful when exporting animations that you use a player which is widely available (don't assume everyone will have the version 8 player or even want to download it). Always back-write a couple of versions (version 6 a good bet).
I use a frame rate of 24fps which seems to work smoothly in most instances (if a machine can't play to this it will generally skip frames in the movie anyway to keep speed - this is true of 'streamed' animation with sound, for example). The whole thing is frustrating as explaining these 'issues' to clients convincingly is always tricky.
Oh, and internet connection speed has little to do with it. Once a movie has downloaded, it will play the same on dial-up as broadband (it might skip a bit if you haven't included a pre-loader of course).
You can use a tweening class like http://laco.wz.cz/tween/ to make your animation frame rate independate (ie it always takes x seconds to move this from here to there, instead of taking x frames)
That's a good point 3 stripe, but in fairness, you need to have a good handle on actionscript. It also depends on the complexity of the animation and how many symbols you use etc...
Yes yes yes. I only got into using actionscript for movement this year, but for say, shifting navigation items about, or fading content blocks in/out, it is 400 times easier and more effecient than using the timeline. Different if you're making a cartoon or somefink though!
And it's really easy with something like the Laco tweens... let's say to fade something in:
myMovieClip.alphaTo(100); And voila, a nice 1 second fade.... that's not tied down to your frame rate :)