Resource items do not get deselected if selected resources are removed from underlying resource sets

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create view 1 and add all resources
2. View 1: create selection A with several elements that will share group
3. Create view 2 and add selection A
4. Group view 2 so that several elements are combined into single resource items
5. Create view 3 and add all resources
6. View 3: create selection B with several resources (should be subset of 
selection A, resources should share resource item in view 2, but there should 
be other resources in the same resource item)
7. Synchronize selection B between view 2 and view 3
8. Remove resources from selection A until there is no overlap with selection B

What is the expected output? What do you see instead?
Resource item in view 2 should not be selected any more, but it remains 
selected.

Original issue reported on code.google.com by Lars.Grammel on 9 Dec 2010 at 2:04

[GoogleCodeExporter]

Possible cause: DefaultResourceItem does not update selection/highlighting 
status when underlying resource set changes.

Original comment by Lars.Grammel on 9 Dec 2010 at 2:05