I've encountered an undefined behaviour of CollectioEditor with 2014 Q1 and previous.
My data have 2 levels of nesting: Client -> List<Contracts> -> List<Option>.
Also I use custom template for CollectionEditor to set some properties of RadPropertyGrid for editing List<Option> (dimensions + visibilty).
How to reproduce the problem:
1. Use CollectionEditor for "Contracts" and add new Contract twice.
2. Select second Contract.
3. Use CollectionEditor for "Options" and add new Option.
4. Select first Contract
5. Select second Contract
6. Open CollectionEditor for "Options" ... ooops.. no option presents!
Problem occur even if I use original template from assembly.
The test project can be found here