wasted over 1 month's time,and the wallet can't show much improve!
when open the wallet first time after update,my wallet disappear 0.001*2,
so I disabled the darksend!
can tell us,it's a bug or it's a donate?

Please read the release notes.
It is a transaction fee paid to the miners to process Darksend transactions(denomination). No different than transaction fees in bitcoin.