Just a thought - a tally of unanswered questions sometimes shows when you answer another question via messages.

 

For example, if I answer a new question after sending my response, I get a "reminder" that tells me I have 60 or so unanswered questions would I like to go to the next one. 

 

It is just a quirk or glitch and that particular notification does not reflect actual number of unanswered questions.