First, you've got an awesome product! We've been using your ASP.Net, WinForms and Reporting for a few years and we've produced great results from them...
Ok, old issue... Within Reporting 2013 Q1, can we effect chart series tooltips? I've read the older forum posts saying that it may be coming and now I see in the 2013 Q1 Online Documentation items for things like ActiveRegions but not sure how/if this can make it happen.
Basically, we have multiple line series on a chart each with PointMarks and no data labels. It would be wonderful for a user to be able to mouseover a PointMark and see more information.
SummaryData(i).sValue1 = 0
myItem.ActiveRegion.Tooltip = SeriesName(2)
This produces no compile or runtime errors and the chart looks great - but it does not enable a mouseover effect (aka tooltip) in the chart in the ReportViewer when the user moves their mouse over a series PointMark.