As for the CVR, why is it that we live in a world where a five year old can Google his way through the moons surface, yet CVR's only record a few hours max? In this day and age this is simply inexcusable! In some instances more than two hours are required in order to find the beginning of the error chain.
This is simple, it's down to $$$. Certainly older aircraft are likely to have older, more limited CVRs fitted, and unless one fails, there's no incentive to pay money to fit a newer, better one unless the rules change that mandate it. I don't know the cost difference between a 30-min and a 2hr CVR, or if it's just that newer technology means that they upgraded them because it was easier. It's a bit like hard disks, you can't get smaller ones any more because people don't make them, same with flash memory used in CVRs. At some point the smaller stuff gets more expensive because less are being made. There was talk after the AF accident over the Atlantic that having a decent satellite uplink to transmit such data would be good, but again, it's $$$ for something that hopefully would rarely be needed.
I wonder at what point they pulled the CB on the CVR as well, delaying that until shutdown at the gate has erased important information in the past, not through any deliberate act, just because it's not exactly a priority item if you're trying to get a damaged aircraft safely down.