Clarification on BIP CatalogService Web Services

I'm on version 11.1.1.5 with the december update applied for BI Publisher.I'd like to use the CatalogService web service (http://docs.oracle.com/cd/E21764_01/bi.1111/e18863/catalogservice.htm#T569715) to update reports/datamodels.

I'm looking for clarification of what the "updateObject" method is supposed to do.  My understanding from the documentation is that this would update the report/datamodel with the data passed to it.  It doesn't seem to work though.  The web service returns true, but nothing changes on the actual object I'm trying to update.

For testing I'm using the CatalogService.getObject to get an object in a byte string.