Embedded flash menu causes html pages to jump

I have inserted a flash menu into the html pages in my website. I am using the same swf file and ebedding a variable name in each page eg. “menu.swf?x=about”.
I then use a conditional statement in the actionscript to determine which page i am on eg
else if (x == “about”)
{
mc_menu.about._alpha = 50;
}…
All is working well except when you click a button to change html pages - the page flashes and jumps. Also in IE i have to click the button twice.
The code behind the button is;
on (release) {
getURL(“index.html”);
}
I would appreciate any help!