When opening files from the DS Toolbar and navigating to a folder of .dwg files; pre-existing files preview OK (regardless of platform from which they've been created and saved i.e. ACAD or DS). If I open a file, work on it and save it as a new file, the preview is generally a solid black rectangle - but sometimes has a highly magnified image of a small portion of a drawing within the black box.

Is this a problem with Version V1R2 (OS = Win 7 64bit Pro) or is there a setting (I've looked but can't find 1) to enable previews to be created when saving the files. I've not had this problem in any prior version & I've used them all from Beta release up.

Files are A3 or A2 size and have been zoomed to 'FIT' the screen prior to saving.