Since returning to the game last week, I too have experienced this bug a few times in various aircraft. The icon suddenly disappears then reappears intermittently. It is definitely happening inside normal icon range with no obvious reason for it to disappear. The first time I saw it, I thought some bombers had bailed - the 3.5K icon was there one second, then gone, then reappeared. The second and third time I started thinking maybe it was just a glitch related to arena lag (which has been bad for me lately). Now that I am aware others are experiencing it, I will relate specifics if/when I see it again. (Not at my home comp now, so can't provide hardware details ATM.)
Anecdotally, it seems to me like it occurred when transitioning into a front-quarter (forward left or forward right) view, but that could be a red herring. It has occurred several times, so I will be looking for it now and will relate more specific and useful data and/or film.
<S>
Ryno