Drawings always update and need re-saving y?

I have a simple assembly and a drawing of that assembly but every time the drawing is opened, when I go to close it, it needs saving, even though there are no changes.

This causes a revision jump in PDMworks as it sees a change and needs to check in.

I have started to traffic lights on the BOM in the feature tree that Ctrl Q will not shift, only by closing down the drawing and re-opening it, will the traffic lights go.

So I removed the BOM, re-saved, but the problem persists.

I have tried this with mutiple drawings old and newly created, still the same problem.

This has once again started with 2009 sp4.1.

The last time I saw this was in 2007

Solidworks pro with Pdmworks 2009 sp4.1

Any ideas or fixes yet?

SolidworksDrawings And Detailing