If it doesn't indicate a hit, this is because either the angle you fired at/the location of the target causes the rocket to hit something else, or you hit the tank say in the front armour and it didn't do anything, or if it's being repaired when it hits as it appears that hitting it whilst it's under repair negates the damage.
It may negate the damage but surely your crosshair should indicate that it actually hit the tank instead of having you wonder did it even hit in the first place? The tracer system at the minute does seem a bit flawed in the sense that rockets will often just bash against hills or walls regardless of the direction or angle you put on it. That being said maybe its because this map has a lot of hills, on something like Arica it may work fine.

How the hell will they find glitches, bugs or other **** on any other map? by internal testing? *lmfao*
That's strange. I run my i7 at stock speed (still) and have got 5850 and I run all maxed out in DirectX 11 (1080p, all high, AA x 8, AF x 16, Vsync and HAOB (?) on) and still got more than 40fps. It is very rare it goes under 30fps for a second (if a lot of smoke around) Oh and Win 7 Ultimate 64 bit