I doubt if it is the system. The exact same behavior manifests in all computers that I have tried these docs, and they are all modern machines with adequate RAM, new OS and new Office. Also, there seems to be some threshhold for this behavior. The size you cite in your test is well within the bounds of what still works quite well. If you want a test of the sizes I am dealing with, duplicate the text to get 15,000 pages, instead of 375.