Outlook name cache file not updating

I've noticed that when I have Outlook (v2003 on Exchange server) and Ootd (v1.41) running, then close Outlook, there is still an outlook.exe process running.  This is only a problem in that certain files are not updated as they normally would be on an Outlook exit.  My outlook.xml and outcmd.dat files always seem to reflect the new time/date stamp, but outlook.nk2 does not.  This is the file that stores the name cache when sending a message, so what I'm seeing is that the names are there during the day - when I compose a new email, names are suggested from those recipients that I have previously sent to that day - but then the next day (after closing Outlook and rebooting) they're gone and only the name(s) from the old file, the last time it was saved, are there.  When I check the outlook.nk2 file, the time/date stamp is from the last time I ran Outlook without Ootd, which I only did to test.

Has anyone else experienced this, or know of a way around it?  I've tried deleting the nk2 file and letting Outlook re-create it, and I've also created a new Outlook profile.  I am able to avoid the issue by not opening Ootd, but every time Ootd is open, the file doesn't update, so I'm pretty certain it's related.