RFC_ERROR_LOGON_FAILURE: Name or password is incorrect (repeat logon)

Hi,

My application on portal is getting the following error.

com.sap.mw.jco.JCO$Exception: (103) RFC_ERROR_LOGON_FAILURE: Name or password is incorrect (repeat logon)

I have tested the JCo successfully. Also, we are using username and password, not SSO.

I read in earlier posts that this error is because of incorrect username and password. But both are correct and my JCo is tested successful.

Can someone kindly guide me as to what could possibly be the problem?