Well, that was unexpected.

Because of the nature of DISTINCT and MERGE subscriptions we decided to force the "scroll behavior" on the grid for DISTINCT subscription and the "table behavior" for MERGE subscriptions:
a DISTINCT item ideally is used to represent a list of things while a MERGE item represents something whose status changes. See section 3.1 of http://www.lightstreamer.com/distros...20Concepts.pdf for details.

In any case, if you can describe us your use case, why you want to use a MERGE subscription to feed a scrolling grid, we may re-evaluate our initial decision (well that's what the beta is for) or show you how to obtain the same effect without modifying the library on our side.