Evertime I push stop. I get a terrible screeching noise. Am i doing something wrong? Thanks

well, darkstorm, you really are gonna have to throw us a bone, here!

only when recording or when playing?  if when recording what are you recording? 
where does the screech come from?  speakers?  headphones?  are they hooked directly to the FW1884?
which driver mode are you using?
does this happen with every project or just one?
does this happen when playing youtube or mp3s or just in MC?
which version of MC?
which version of windows?
do you have another soundcard connected?  do you have speakers connected to your onboard soundcard?  are you using that as well? 

give us as much info as you can.  we can't see what you see or hear what you hear!

oh.... I have heard that too. Is this coming after a fresh reboot? When I hear that.... it tells me something in the memory resident parts of the program have gotten corrupted somehow....and I do a 100% shut down of the computer AND the interface and restart them both.

Check your drivers to be sure the drivers are the right ones. If the interface supports ASIO be sure to use it. 

It happens when I push stop when there is an audio file playing in a track. a loud screech noise from the speakers. it goes away if i push play again.
This does not happen in sonar le ver4. I am using mc6 build 50, windows 7 64bit 
 Thanks for help. I'll keep messing with it

Thanks for helping. Not sure why but if I have at least 1 vst instrument loaded the high pitched screaming sound is no longer present when I push stop

It's kinda hard to know exactly what you are talking about without hearing it. 

I have heard a zipper sounding noise when stopping playback, I have heard other sounds and I have had sound freeze ups where the noise continues until a reboot is initiated and the noise stops when the audio shuts down for the coming reboot, and also hung synths. 

If adding a VSTi solved it.... glad to hear that.... but I'm still curious since there would generally be some other sort of underlying issue that caused that screeching.