Hi, I have a buffered grid in ExtJS 4.2 which is working fine. Code is shown below:

title: 'MyGrid',
closable: false,
xtype: 'gridpanel',
id: 'mygrid',
store: {
storeId: 'mystore',
model: 'MyModel',
buffered: true,
pageSize: 20,
purgePageCount: 0,
trailingBufferZone: 20,
leadingBufferZone: 20,
scrollToLoadBuffer: 10,

proxy: {
type: 'ajax',
url : 'http://www.myurl.com/MyServer/GetData?limit=25&offset=0',
reader: {
type: 'json',
root: 'job'
totalProperty: 'count.count'

Initial call is done dynamically like:
Ext.getCmp('MyGrid').getStore().load({ params: { newParam: value} });
where a new param 'newParam' is added to the call.

The problem is that in automatic scrolling calls, successively done by EXT JS framework, this parameter 'newParam' is not longer passed. I would expect that successive calls would repeat the first one, but they just invoke the url specified in the proxy. Otherwise I would expect a known mechanism to modify params in these automatic calls.

* What is the expected mechanism to include this dynamic parameter on automatic calls performed by the buffered mechanism?
* Otherwise, where can I intercept the flow to add this 'newParam' for automatic scrolling calls?