Unfortunately, lots of web sites are only made by people with knowledge about graphic design. They only take into account the more fashion FX effect, the best good-looking layout (for their taste), and this type of things. Compatibility and navegability are usually forgot. Why spend time on these aspects, if the boos or the business who is paying us only wants a good looking page. And, anyway, designers know how to design, so they have to convince its client that design is the most important thing of the world. So, this means that lots of web sites are entirely made with Flash, or do a heavy use of it. I complain thinking on all the blind people that could never navigate through these sites…
Related to this, there is another problem: Flash is a propietary technology. Free viewers, but propietary. So, Linux users are having lots of problems with webs that use the cutting edge multimedia technologies, such as the last versions of Flash. Why? Because adobe (the actual owners of Flash) have not released an updated version of its player (the later stable version is 7).
But, lately, I have discovered a beta version of Flash 9 for Linux (yes, version 8 does not exist). I have used it, and it solves most of the problems I was suffering, such us invisible text or desynchronized audio. You only have to download it from the adobe site (the Installer, not the Stanadlone player), take the .so file, and put it on your personal mozilla plugins directory (usually $HOME/.mozilla/plugins/). You can check if version 9 is installed putting into the address bar this: “about:plugins” , without the quotes, and looking for the information of the Flash player.
But, in my opinion, the best solution should be not using it, and use open technologies. For a better society, you know… ;)