Q: Mail being read deselects??

I am having an issue with various emails that deselect while I am reading them. I will see the "no message selected" in the background as if I never selected an email.

This happens a couple three times a day.

When it happens I do not have my hand in contact with the mouse or the keyboard. It is frustrating especially when I may have 20 or 30 emails from that day and not necessarily processing them in chronological order. I then need to go through emails I have read to find the one I was currently reading.

Any ideas greatly welcomed.