You should post your grid questions in the grid forum. It will allow the grid engineers to more readily see them. Also, if you require a timely response for your questions, you may want to use our Direct Trac support system as that forwards your questions directly to a support engineer and tracks the issues until things are resolved.
To see caption summaries in nested tables, you need to set the properties on the NestedTablesGroupOptions. Here is a little sample that shows caption summaries in nested tables.
http://www.syncfusion.com/Support/user/uploads/GGC_NestedCaptionSummary_a4eddea7.zip