Flash slower in browser than in the Dev IDE

Ive been working on a game on and off for a while now. I’ve been extremely conscious with the performance because in my book a slow game is worse than no game at all. I even wrote a profiler class so I can really pinpoint any slow code.

All this time Ive just been testing the game in the Flash CS3 environment by hitting CTRL+Enter. And everything runs quite smoothly.

But today for the heck of it I actually published the Flash and ran it in my browser using the generated HTML file. In the browser everything runs slow as hell! The animation is extremely choppy, and sounds play up to 1 or 2 seconds later than theyre supposed to. This is absolutely unacceptable! Ive tried it in Firefox3 and Internet Explorer 7, and both are very slow compared to the Flash dev environment.

This is so frustrating! Whats going on? Do the browsers not use the same flash player as Flash CS3?