Trouble Accessing Schema-Qualified Table

Hello,

I need to access a database using two different schemas.  During initialization the default schema is set as follows:

set schema 'ucm';

Then later, I need to get data from a table in another schema 'ts_sofia_internal', so I tried the following, but it returns an error as shown:

teo=# select * from sip_presence('ts_sofia_internal') where sip_presence.sip_user='1003';

ERROR:  function sip_presence(unknown) does not exist

LINE 1: select * from sip_presence('ts_sofia_internal') where sip_pr...

                      ^

HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

teo=#

Does anyone know how I can do this?  By the way, I'm using odbc to connect to the database.

Thanks,

Jerry