SQL 2005 Schema Problem After Installing SSIS

I restored a backup from SQL 2000 onto a new SQL 2005 server. The
database restored and the matching user who was the owner of that
database in SQL 2000 was created as a user in SQL 2005 as well as being
designated as the "schema" for that database. I was having
trouble logging in with the user that was created after the restore, so
I created a new user and assinged the new user as DBO of the new
database, set up the new users default database and schema, and
everything was working fine, my database driven application worked
perfectly under that user.



Then I installed SSIS, as it was recomended as a solution to another
problem. After installing SSIS I can not run queries without
specifying a schema name. For example this query will not work,
it returns table not found:



SELECT * FROM <table_name>



However if I specify the schema name like this, the results return:



SELECT * FROM <schema>.<table_name>



This screws up my database application as it does not include the schema name in its transactions.



I do not understand why installing SSIS would have changed this.