ok suddenly started working again...
Found another work around...
IF you have a complex MDO run the time domain may run short enough that you will end up with GIGANTIC data sets, and then they will not import into Excel directly out of MDO...
There seems to be an issue between MicroSoft and MDO's export, from best I can get if you have some where over 36k output data points to plot it is a no go...
BUT...
You can write from the graph function in MDO to a Text file, that comes out with the extension..
<your file name>.grt
JUST CHANGE THE EXTENSION to ... <your file name>.xls and open with Excel, no graph but at least you have the data. I just cut / paste into a workbook I keep filling in as I make iteration of the design.
Downside is you can only export one measure at a time with this method.