We are having a problem with zooming when we have simple line charts with a few thousand points (otr multiple lines with less points).  We can zoom in three of four times with no noticeable lag.  However, we then reach a point where any subsequent zoom (in or out) takes a very long time, and, in some cases, the chart control just becomes completely unresponsive and we have to crash out of it.  Trying to zoom out (which is set to a complete reset of the chart) is the most common way we can get the control to hang. Is this a known issue?