I hate to state the obvious, but it is quite difficult to diagnose your problem without a circuit diagram or circuit file. I haven't posted any circuit files to this forum so I have no idea on how to do that.
O,K, First, be aware that I simulated this with 2001 version. Your LED does Flash faster as you crank the pot down, but it is just a slight variation. I calculated the frequency changes from about 15 Hz down to 13 Hz (if my math is correct). Not much of a difference, therefore may not be really noticiable with the LED, but you can see it with the O-scope (barely).
You may have to re-calculate your component values, especially the capacitor value, to get it to flash faster. Can you tell us at what flash rate and range of flash rates you would like to see? Maybe we can tinker with you values and come up with something to suit your need.