The styles will get disposed eventually. The default GridVolatileData implementation has a collection of WeakReferences to the GridStyleInfo objects it creates. Once garbage collection collects these instances they will get disposed. (There will be a huge difference between release and debug version when they are collected).
You have the option to provide your own GridVolatileData implementation. For example, the GridPerf example implements a different solution when you don''t need QueryCellStyleInfo callbacks.
Attached find also a modified VirtualGrid sample that I creatd recently and uses a modified GridNonVirtualVolatileData class. Just in case you are interested in investing this option further ...
In that sample QueryCellInfo is only called once for a cell. Then it gets stored in the same style cache that we used in GridNonVirtualVolatileData class and after a cell was initialized the QueryCellInfo event will not be raised again for that cell.
Stefan
OneTimeOnlyQueryCellInfo_140.zip