LTSCALE Changes in DWG when opened in Mstn

We opened a bunch of DWGs in Mstn V8i ss4 and made a single change to a Tag in each DWG, now when we open the DWGs in acad all the hidden lines  ie dashed has  LTSCALE = 1 for the lines and if we keyin LTSCALE it tells us the LTScale is 500 ( we are working in meters) ...

We want the  LTscale to stay 0.5  before we open a DWG in Mstn and to stay 0.5 when we close the DWG... is there a setting in Mstn I'm missing or stuffed up....?

This never used to be a problem in V8iSS3.... I used to edit DWG title blocks all the time with no effect on the LTscale of lines... or maybe they were already set to 1 and  we never noticed...

But now we are noticing as all lines look like type 0 or Continuous   not good  please anybody got an idea.