why worry over bandwidth cap? already happened to you? thing of past
Look http://en.wikipedia.org/wiki/Network_neutrality (footnote 21)
me have 5 computer 2 laptop 2 vp200 several other vp with time wanrer no problem
use port forward not dmz
connect vp200 to wrt54g and use dhcp to get address from wrt600n
then uncheck dhcp and set up pf on wrt600n dont have be on 192.168.0.125
go ahead try dlink i2eye to see
me suggest take your vp200 to different location like friend house 50 or 100 miles away and try their internet to rule out your DSL problem
try dsl modem at MPOE as the only connection to rule out house wirings