I just wanted to post my progress in case it helps someone else.

I continued to have the problem using 4.7 with the random (pretty much immediately) log off of AD users.  I saw a blog post by Mike which showed that he was able to fix this problem by deleting the existing users (luckily, I have this luxury as I'm starting from scratch without existing users).  In my case, the aspnet_users table wasn't consistent with the users table (I think I deleted user table entries using SQL Manager before I was aware of the sister aspnet_users table), and in my testing I was logging in with a couple users who existed in aspnet_users but not in users.  I think this is the reason for the random log offs.  I removed the accounts from aspnet_users to reconcile with users, and now after logging in the authentication is stable.

Kel

Thank you Mike,

Rewrite the <impersonate="true" userName="domain\user" password="password" /> solves my problem,

-Oliver