javascript - Ext JS store unexpectedly reloads data when it should be buffered -

we trying work off of example: http://dev.sencha.com/deploy/ext-4.0.1/examples/grid/buffer-grid.html

e.g. in store:

// create data store var store = ext.create('ext.data.store', {     id: 'store',     pagesize: 50,     // allow grid interact paging scroller buffering     buffered: true,     // never purge data, prefetch front     purgepagecount: 0,     model: 'forumthread',     proxy: {         type: 'memory'     } });  //and in grid: ... store: store, verticalscroller: {     xtype: 'paginggridscroller',     activeprefetch: false }, loadmask: true, ... 

but when scroll past pagesize records in grid, long pause more next set of records being rendered -- store reloading data our web service. call our web service loads of data , don't want re-loaded when user scrolls. want rendering buffered, not data loading, example states "his example illustrates loading of records front , buffering rendering." because want avoid moving sorting , ordering server @ point performance. yet don't want rendering right away because leads dreaded long running javascript error in ie8. thoughts on causing store re-query data source in mode?

if want records loaded , rendering buffered need set buffered:false on store plus need use buffered grid view renderer.