well i was a bit hesitated, first time for me to post ay any forum..no big deal hah

i have a 512/256 adsl connectionin im using d-link DSL-500t router, surfing and downloading of any http site is fine i get 50/60k
except dc++ my download speed always less than 10k, and if i browse any site while downloading from dc++ my connection gets better it start to increase (it also reach about 12k), when only dc++ is running it starts to decrease as usual i tried everything possible to fix it, i did the port forwarding and enable dmz update to xp sp2 tweaked the the xp tcp connection limit thing and many other tweaks but still the same problem i have no spywares viruses my xp firewall is off and my routers firewall also if off i tried everything possible downloading from many diffrent users...i just dont know what else to do...so can anyone help me please im so desperate...