I'm giving a final update on the problem.
1. I have two ways to access "Favorites" in Explorer - I don't know what the difference is between these two, but one is an icon of a star, next to which is the word Favorites. This icon is immediately above the Explorer window tabs. The other way is just the word Favorites, located below address window, and is among the words "File, Edit, View, etc." One day I noticed I only had the problem of the willful cursor when I tried to use the star icon. I didn't have the problem when I used the word Favorites under the address window.
2. I'm not sure when the willful cursor problem started, but recently I told someone that the Computer Associates (CA) antivirus, etc. service that comes free with Roadrunner was REALLLLLY SLOOOOOOOOOWWWWWWWING down my ability to access my files and to search the internet. She suggested I switch to Microsoft Security Essentials. My computer immediately rocketed back to high speeds, and I just noticed that I no longer have the willful cursor problem when I use the star icon to access my favorites.
So, Case Closed