Issue: Issue with PM box [RE-OPEN]

Hi,

My PM box keeps showing 1 preselected message. When I do "Deselect all messages" from menu, it disappears for some time, but when I revisit the site again then the notification is back to "Selected Messages (1)" in options drop down at bottom of page. I am sure even if I had originally selected any message, if it got removed by "deselect all messages" then it shouldn't come back again. But somehow it does; only started having this problem after the update.

I've already checked all my folders, inbox and sent items; I do not see any message that has been selected.