Strange problem with 10G using client installed enterprise manager console

Question

I have successfully installed 10G on our SUSE linux 9.0 server, I have created 6 databases (standard edition of the database) and verified their parameter files, control files, and database files are in different locations --- all done at the server console. I created my DBA account on all 6 databases and logged into each one to verify their function.
I returned to my PC where I have installed the 10G client and where I have used the 8 and 9 enterprise manager console to manage my databases. I got the TNSNAMES file in order for the new databases. I logged into the first database and tested my workstation connectivity successfully , I logged into the second database and it said my password was incorrect. I ended up signing in on the second database with my first databases account password. (it then worked). I got fed up hopping around with the mystery with the password being stored somewhere in the enterprise manager java ? and logged in as system and changed all of my passwords. I then went up to the console and found that the only database that they changed on was the first one.
I returned to my workstation and started creating the data files and users and roles in the first database. I now on either workstation in my office, when logging in as ANY of the six database DBA accounts, can see all the objects I created in the first database.
I went to the server console and logged in and verified that the objects only exist in the first database. For some reason the enerprise manager console is really a problem. I have windows XP. Our database is on 10G but we are not taking advantage of grid control due to budget reasons (one server only).
I have heard there is a url based web management console at: http://serverip:5500/em, but it is not working currently in our environment and it will be up to our sys. engineers to release / open up that port through our DMZ. Ordinarily would this allow the kind of control that the old enterprise manager console would?
Is my installing the grid conrol product going to be "overkill" and not useful for me or should I install it?
Is there an alternative 10G version of the enterprise manager console for simpler environments like mine?
Is there a good explanation why my workstations are presenting "false" cached information above what is really in the database for objects unique to each database - ie: why are my #1 database objects showing up in EMC as objects in all databases and why is EMC managing/storing my passwords.?
I just need to get the best choice to manage my environment.
I know I have asked a lot of questions and I would appreciate any insight from someone who has encountered this before.

Answer 1

fixed
- the alias in the TNSNAMES was correct but the actual database "service_name" was the first db - -- a long project / late night oversight. I also went into the sysman\ifiles\ and corrected the entry for the database there too where it had registered the settings for the wrong database.