Compared to some other programs (*cough* Director *cough*), Flash is pretty much "glitch free", although it still does have some bugs or other annoyances. Lucky for you, I've already encountered (most of?) them.

This is a good reason to save often. Sometimes, using the brush, or less often the eraser or pencil, will just cause Flash to crash. Normally this happens when making a very long complicated line without releasing the mouse. This is required sometimes, so just save often.. it's not that common.

At one time or another, you'll be trying to draw with the brush inside a symbol, and nothing happens. Frustrated, you may just draw a crazy mess of lines everywhere.. and then suddenly it does draw... just the reverse of where you drew the lines. :o

This seems to be a problem with transformed symbols, in particular, reversed (flipped) ones. If you create a symbol, and flip it around (using "Modify -> Transform -> Flip Horizontal / Vertical", or with the "Fee Transform Tool"), you won't be able to draw in it properly.

A workaround is to copy and paste your symbol somewhere else, and use "Modify -> Transform -> Remove Transform" on it. Edit the copy, and since it's a symbol, the original will be edited too.

Although there is a very small chance that you actually are a chipmunk and/or Thor, it's more likely that you saved your recorded voice as a .wav file. Sometimes Flash speeds up or slows down .wav files when you import them. Try to save as .mp3 if possible, or find a free converter. (Flash converts everything to .mp3 anyway.. which is probably where the glitch lies)

I don't know if it's a bug or what, but it seems to happen to everyone at some time, usually with longer movies. The sound won't just go out of sync.. it will actually start playing something like 5 seconds late. I've heard of and tried a couple solutions to this. The simplest one is to create "blank" constant streaming sound. Create a new sound in a program like Goldwave (or whatever you're comfortable using), just 1 second long, and silent. Import this to your movie, and on a new layer, place your "silent" audio track, and set it to repeat 999 times, or loop. This should keep everything in sync. According to my own test, this doesn't increase file size, although I would expect it to. Another more complicated method is to cut and paste your whole movie (except the sounds) into a graphic, and put the sounds in a movie clip which plays along side. Sometimes this doesn't seem to have any effect, and if the user pauses the movie, the sounds will keep playing. Recently I do this anyway, just so I can do "camera movements" or "shakey screen" effects by moving the whole scene around. (But without putting the sounds in a movie clip, because that just makes things complicated.. keeping them on the main timeline along with a blank streaming sound seems to be the best solution)

I haven't discussed filters in this guide; they are a new feature in Flash 8, which allow you to blur movie clips, or apply other effects. Anyone who hasn't updated their Flash Player to the recent version will not be able to see the objects with filters applied to them. Not just the effects.. the objects themselves will be invisible. This also seems to happen with some text options. It can make a movie look horrible, or a game not even work. There are basically 2 ways to prevent this.

1) If you don't really need to use any Flash 8 effects, and you were just going to throw in a random effect or two for no particular reason, don't. If it contributes nothing / not much to the movie, it might be better just to do without it, for increased compatibility.

2) If you were planning to use a bunch of filters etc, or you just don't want a "half-assed" version of your project viewable, you can prevent it from being viewed with actionscript. There is apparently some code to check the Flash version, which I haven't bothered examining yet. So far I've just used a work around. (actionscript knowledge required) I create a 2-frame movie clip on the menu and/or loading screen. The first frame contains a giant button over the screen to prevent the "play" button being clicked, with the message "Your Flash player is out of date, click here to update", which leads to the Adobe Flash Player page. There's also a blurry object, which will only load if the user has Flash Player 8+. The blurry object contains code that "onLoad", the giant button should go to frame 2, which is blank. So the user will only see the message if they don't have Flash Player 8+, and the code to make the message go away never loads. If that was confusing.. hopefully you get the gist of it.

As time passes and more people upgrade, this isn't really a big issue. Already, most people seem to have upgraded.

If you have access to a second computer or laptop, it's useful to install an old version of Flash player (available from the Adobe website.. use google.. or, here's version 7, courtesy of me). That way you can test what your movie/game looks like to old players. (as long as you open it with a web browser, not from your desktop) Here's what Via Sol 2 looks like with version 7 installed:

There isn't (currently) any guide to ActionScript here (try Kirupa.com). But, I'll put some potential frustrations you will likely encounter here.. once I remember them. (I assume most people looking at this guide were NOT looking for ActionScript debugging tips.. so it can wait for a bit.)