Word 97 hangs in Windows 2000

We are in the process of moving from Windows 95 to Windows 2000. The problem only appears in Windows 2000. When you double-click on the Word icon, nothing happens for approximately 1 minute. Eventually it will open but anything you try to do involves a major delay and ultimately stops responding. If you reboot (sometimes once, sometimes 3 times or even 5 times) it straightens out and everything is fine. Here's where it gets wierd: it doesn't happen to everyone, and it only happens sporadically. One person has it happen 3 to 5 times a week. Another person twice a month. Out of 40 W2K users, approximately 15 experience the problem. In each case, rebooting straightens it out. The only common denominator is Windows 2000. We tried recreating the normal.dot, bypassing startup files, reinstalling Word. I've run out of ideas.....