I seem to have an issue on windows 10 Gateway laptop, i3 cpu 6gb ram. Each time i close and re-open the wallet, it seems to need to rebuild the blockchain, a small annoyance now, but when the chain grows and takes a few hours to sync, it could be very troubling.
Yes this is due to annother problem, it rebuilds the index of blocks, now that the draft wallet is done i think that i will on this problem.
But regarding rebuild time, it takes a couple of seconds to me (windows 10 4cores multithread i7 3.8 8gb ram)