enableSmartRendering and reload data in grid

first I load the grid well and smart rendering works well (it calls the function to add new data each 100 rows);
then I simply change the dataset, clear the grid, reload the data: now smart rendering stops to work: only the first 100 rows are visible, and the function isn’t called anymore;
what could it be?

… the most significant part of the first initialization …

  objGrid[gridIndex]=objTabBar.cells(onKey).attachGrid();
  objGrid[gridIndex].setImagePath("Styles/Imgs/");
  objGrid[gridIndex].setSkin("dhx_skyblue");
  objGrid[gridIndex].i18n.decimal_separator=",";
  objGrid[gridIndex].i18n.group_separator=".";

/* this is the parameter with the first selectedID filtering data on the server */
objGridQString[gridIndex]=“Job.Aspx?WHAT=JOB&PAR=SHOW^WHAT^LOAD_GRID^MASK_TAB^”+onKey+"^SELECTED_ID^"+selectedID.toString();

  objGrid[gridIndex].setInitWidthsP(Grid_Col_Widths[onIndex]);
  objGrid[gridIndex].setColTypes(Grid_Col_Types[onIndex]);
  objGrid[gridIndex].setColAlign(Grid_Col_Aligns[onIndex]);
  objGrid[gridIndex].setColSorting(Grid_Col_Sorts[onIndex]);
  objGrid[gridIndex].init();
  objGrid[gridIndex].enableSmartRendering(true,100);
  objGrid[gridIndex].enableAlterCss("even","odd");

/* first time works well! */
objGrid[gridIndex].loadXML(objGridQString[gridIndex],GridDataLoaded);

  objGrid[gridIndex].attachEvent("onBeforeSorting",GridSorted);
  objGrid[gridIndex].attachEvent("onRowSelect",GridSelected);

… when I do the refresh …

    objGrid[actualGridIndex].clearAll();
    objGridQString[actualGridIndex]="Job.Aspx?WHAT=JOB&PAR=SHOW^WHAT^LOAD_GRID^MASK_TAB^"+onKey+"^SELECTED_ID^"+selectedID.toString();
    objGrid[actualGridIndex].loadXML(objGridQString[actualGridIndex],GridDataLoaded);

-> selectedID changed between the first and the second call
-> only the first 100 rows are loaded

somebody knows the reason and how should I reload the right way?
thks!

Unfortunately the issue cannot be reconstructed locally.
The similar code works well for us.
If issue still occurs for you - please, provide us with a complete demo, where the issue can be reproduced.