Data Base Administrator

[SIZE=7]hello[/SIZE]
any one could tell me about database administrator.
i want to connect oracle management server for import database of sql server 2000, i new the its
user : sysman
and also its password.
it is connected first time and i change its password
now i am trying to connect it but a msg is prompt

"VTK-1000 : Unable to connect to the management server (server name). please verify that you have entered the correct host name and the status of the oracle management server"

plz tell me as soon as possible......
i will be thanks for all....

This is oracle issue. Where did you change pwd? Tried with old pwd?