new problem in grid control

hello ,
i have installed the grid control 10.1.0.3 on oracle 10g 10.2.0.1.
during installation it gives one error about enterprise manager repositorry agent is failed. but i ignored that and continue the installation.
after installing it when i give the relevant enterprise manger url i received the following error displaying that.
"503 Service Unavailable
Servlet error: Service is not initialized correctly. Verify that the repository connection information provided is correct."

plz give me some idea of solving this problem.
with regards,
waqar.