Populating COM+ Collections
After you have retrieved a collection and before you can work directly with the items it contains, you must populate the collection by using the Populate method. This fetches data for the collection's contents from the COM+ catalog.
It is important to understand that whenever you use the COMAdmin objects to manipulate items or data in collections, you are really working on transiently cached data; you are not working directly with the persisted catalog. Nothing that you do with a collection or any of its items is reflected on the catalog until you call SaveChanges on the collection. For more detail, see Saving or Discarding Changes.
Any subsequent calls to Populate, prior to calling SaveChanges, has the effect of discarding pending changes to all items in the collection. Populate always populates the cache you're working in with whatever data is persisted on the underlying catalog data store.