Kyle, thanks.
I am perplexed as to why it only happens after the first time that I access the menu item after login. However, it only happens periodically in that context and not consistently. One would think that if it were an issue with a menu link, that it would always happen. Also, the fact that logging out and logging back in fixes the issue suggests that it may be an issue with the CB login module.
However, I will check the URL as you have indicated (the next time that it happens).