Ok heres what I do, I find the dry weight in the aircraft.cfg file to be 129294lb's, add that to the fuel I loaded 26770lb's and add that to the weight i added via the ACE which is 42956lb's.  This equals GW199020lb's.  I try to input this into the GW section of the CDU on the PERF PAGE as 199.0 and still get an INVALID ENTRY message.  Ive tried inputting this figure in different forms ie 199.0, 199.02, 199.1, 199020 etc but still get the INVALID ENTRY message.  Also each time I try and use the payload manager in FS itself I get a CTD.  Scratching my head on this one!  :-?

Rich