The Teamcenter you are connecting to, does it have ActiveWorkspace?
The SOA you are using for searching is most probably performSearch which uses the provider and that provider is in ActiveWorkspace. If you just want to work with Teamcentr and no ActiveWorkspace then you will need to use executeSavedQuery SOA call for performing search operation.
In Teamcenter Connector Sample app, Item Revision search is using executeSavedQuery search(ActiveWorkspace independent) and other 2 i.e. General Search and ItemSimple Search are using performSearch(ActiveWorkspace dependent).