I've had that happen also, and my squadmates also report it. I've been meaning to make a bug report, but I'm so damn lazy...
Anyhow, this definitely happens and as best as I can tell it ALWAYS happens. Since I think anyone would be hard pressed to show me a real armoured vehicle that does this endlessly on the battlefield, well, then I guess we have to call it a bug..
So if HT would please fix this 'undocumented feature'... I'd be a pretty happy camper, 'cuz I gotta tell you its damn hard to shoot a heavy 51 when you're bouncing around like a lovesick poodle.