This is what happen....

1.- I open a large top-down assembly...
2.- Then from inside the assembly I open on his own window any part for editing... after editing the part (or even without doing nothing) I save the part and "close" it returning to the assembly... and repeat this for several parts...
3.- Then I open a sub-assembly on its own window... edit it, save an close..
4.- Then open a part on its own window and leave it open... also open a sub-assembly or another part on their own windows... and return to the main assembly...

And suddently... when trying to change to one of the open widows (Window... select open document to view) SW show a window with a part that it is not even open (normally one of the parts opened on item 2 above), then you close that part... but it never close... the only way to get to the open document I want is by doing "Window" >>> "Browse Open Documents" and select the document from one of the Icons show on the "Open Documents" window.

Is this a "bug" ??? if this is the case, apparently no one reported since on the Knowledge Base is no reference at all to this problem... and we have it every day...

We wonder if it is a probelm with our installation... but it is happening on all our machines, since we installed SW 2008 sp 3.1 (we work on Windows XP Pro x64)

By the way it is not a video card problem, we have a "certified card and a certified driver"....

If we are the only ones with that problem them we deserve an award or something... perhaps a medal from SW...