The trick to traffic shaping is setting your upstream pipe size.  I use the 
"Traffic Graph" to monitor outgoing traffic and under a saturated outgoing 
file transfer.  I then lower the pipe size a little bit at a time until the 
graph changes from a wavy line to a fairly straight line.  The wavy line 
indicates you are not the one limiting your outgoing traffic where as the 
straight line indicates you are the one controlling the maximum amount of 
outgoing traffic.  Also, I only traffic shape outgoing and not incoming 
traffic and my Vonage VoIP adapter works flawlessly 95% of the time.

Roy...