i dont think there was a lot of laptops shipped with the B2 bug but still check to be safe, if it does though do ring acer and tell them you have the version the the motherboard bug as the effects are not noticeable within a short amount of time(it takes something like a few years for the bug to develop) and if acer does not give you the choice for the replacement/refund then it should be fine in the meantime, but when it does fail tho, the data on the hdd is not effected, its just a port failure. or if your laptop has SATA 3 connectors then connect your hdd to that instead if its not already.
as for the website, im guessing that when acer says you do not need service in the defects section its probably that your model was released after the B2 period and there was never any of that model shipped with B2, in that case i would check just in case and if it is the B3 after all then there are no problems