I have found these Silverlight bugs in build 220.127.116.110.
1. Missing references that need to be included for basic controls such as ‘Label’ and ‘NumericUpDown’
2. Duplicate DataGrid Column x:Names
If you have two DataGrids on a view and both DataGrids have the same column name such as ‘Title’ (or any other name) then each grid will have a x:Name=”Title”, this causes designer and compile errors. I suggest you leave out x:Name for all DataGrid Columns.
3. Validation of FinalState
FinalState names need to be unique otherwise it will create compile errors. For example I have 3 modules, each has a FinalState1 pointed to a UseCase in a 4th module, the EventController for the 4th module has three FinalState1 events and Subscriptions which is ambiguous. So in my view FinalStates names need to be unique for the entire solution not just at a module level and validation should also check for this.