My preloading bars work fine on my computer, but get all crazy when put online.. they either stop in the middle and the actual swf doesn't appear, or they don't work at all. How can i solve this?
Have you got event listeners at every stage to make sure all your code is happening in an orderly queue?
If the results online aren't constant, then it's probably because of the order in which things are loading. When you test it on your computer, it all loads instantly, so you don't notice if there is a problem with your load order.
For example, if you aren't checking that your preloader has been instantiated (actually added to the stage) before you try to change the values in it (update the percentage, etc), then you probably won't notice a problem locally, as the preloader will be added quick enough for there to never be a problem. Online, it may take an extra second or two to add the preloader, and that could be long enough for your code to have gone on without it and attempted to update it's values even though it doesn't technically exist yet. It may not be that exact situation, but you get the idea.
Some code would help.