Deleting cells from chart source data, causing problems
 

I've got an embedded scatter chart set up, with each row (and each data set)
in the source data corresponding to a date (ie dates are the x-variables). I
want to delete cells (and then shift cells up) in this chart. I'd just
delete the row (and I don't know that this would fix my problem), but I've
got data outside of the chart source data, and don't want to delete this as
well.

So when I try to delete the cells, I get 2 message boxes telling me a
formula in the worksheet contains an invalid reference, but none of the cells
contain the #REF error message. This leads me to believe that the error's in
the chart, but I can't find a reference error in the chart, either. Can
someone tell me what's going on? Thanks.