Stalling caused by clutch?

[RoushRacing6N17]

My car has been stalling when I am crusing along and push in the clutch to stop. Its like the RPM's just fall right out from under it when the clutch goes in. I don't know if the clutch is to blame but I know that the only time the car will stall is when the clutch is pushed in coming to a stop. I also don't think that the vacuum that the brakes use has anything to do with it, though it seems like it may be vaccum related. Sometimes it stalls as soon as the clutch goes down, but most of the time its when you are barely rolling coming to a stop. the car also seems to idle fine but its like when you push in the clutch and the rpms fall from where ever your running down toward idle it doesn't stop at idle it goes just low enough to stall the thing. thanks for any info