I've been using code with lines like the following for a long time, in many places:
MyPIServer.PIPoints(MyPITagString).Data.UpdateValue(MyNumericalValue, MyPITime, PISDK.DataMergeConstants.dmReplaceDuplicates)
This has always added an additional value (Current TimeStamp). NOW, every time it runs, it seems to delete the previous older TimeStamp each time it puts in the new value with the current TimeStamp.
Any insight is greatly appreciated.