Does this happen to all parts? For example, make a simple block and repeat the refresh/redisplay on it, now if that block also zoomed way out, then it may be caused by another part on the workbench, maybe an untitled part that is not tracked by Manage Bin?
If issue is part specific, and this part has multiple features on it, try rollback on earlier feature and test the refresh/redisplay; By using rollback on history tree, it can help you narrow down the feature causing the zoom out effect.
As far as hardware validation on your new NT box, try the
following certification checklist supplied by UGS:
support.ugs.com/online_library/certification/
Hope this helps,
Mike