I've been getting another pinging problem. This time active sonar brings nothing at all, not even background noise. It's described here:
http://www.sonalystscombatsims.com/phpBB/viewtopic.php?t=926
One thing I noticed though, is that if a contact is highlighted (from a previous, successful ping), it still shows what contact it is in the panel thing.
Is it a bug or is there some reason the sonar display doesn't update?
edit: save+load fixes it temporarily.