cant connect to winboard but getting ping from default ip

hello everyone i just started with Microtik routerOS
i have routerboard 153 with 3 adsl 24mb lines i bought the routerboard with full setup(setup was like eth1 = online games. eth2= http. eth3 = p2p)took it with this setup!!but the everytime someone starts to download something from rapidshare or torrent online games disconect serfing was slow like 56k pstn ! so i thought smthing going wrong with the setup! i saw the forum here and started to play with routeros with winboard!was testing the interface setup and suddenly after i changed smthing in those interfaces winboard dissapeard and when i tryied to run it again i couldnt connect to router so i used the explorer to get in console as i saw from guide here! again i couldnt connect ! the strange thing is that when i ping the default ip from router i get reply i just cant connect to winboard!!! so i m stucked! so can anyone here help with this ? first time in routeros i didnt know how to give u the details u need so i wrote all the story sorry for making u reading all this!!