FM Datasource connections failing

[cognosun]

Oracle database connections from my Framework manager are working fine but one fine day they started failing, giving errors like:

Logon failed, unable to connect, unable to access the___database...TNS protocol connecter not loadable etc

Can anyone tell me the reason..

I'm still able to successfully connect to oracle databases from my Oracle SQL Developer client, from my machine.

[bus_pass_man]

Is it this error?  There's some stuff that I googled about how to fix it.  It's a Oracle config thing, I think.
            ORA-12557: TNS:protocol adapter not loadable