Movies Lagging In Browser

Ok, I’ve been working with flash for a while. I seem to always have the same problem. My sites are always really slow and just lag on other computers (especially macs for some reason).

I just made a new portfolio site that is very minimal, There’s really not much going on and I took any onEnterFrames or anything like that out of my site to save processor usage. It is still lagging really bad! there’s only 3 sections to this site and minimal graphics!

I understand why it would do this if I had a lot of bitmaps and tweens ect. but this is just rediculous now, and extremely frustrating. On one computer it lags like hell in FireFox and then works fine in IE or as just a .swf on my desktop. I don’t understand what would cause this.

I’ve looked and haven’t found any good resources to fix this problem. Is there anyone that can help or point me in the direction for help on this???