sound problems in flash 5

[waterdesign]

OK, I have 2 sound objects, which work fine INITIALLY. MC1=noise, MC2=contact. Noise is the background sound which needs to play behind all pages EXCEPT the contact page (for which, obviously, "contact" needs to play). I can make the inital transacion without problem (stopping noise and starting contact) the problem exists when LEAVING the contact page. I cannot get the "noise" soundtrack to begin again. What am I doing wrong?

//on first frame of background swf (just one from each sound object...)

mySound4 = new Sound(noise);
mySound4.attachSound("crowd"
mySound4.setVolume(25);
mySound4.start(0,999);

swork = new Sound(contact);
swork.attachSound("work"
sworkVolume=100;
swork.setVolume("swork"
swork.stop();

//on buttons leading TO contact page
on (press) {
_root.mySound1.stop();
}

//the call for all sounds in "contact" are made within that seperate movieclip

//on buttons leading OFF contact page
on (press) {
_root.svacc.stop();
_root.mySound1.start(0,999);
}