i did it - there is no error in v6 with 3 privkeys imported from v5
but balance - 5342, net burnt coins - 13324, effective burnt coins - 5856 instead of old wallet - 16758, 19804, 7819 respectively
and the same shit in v5 new wallet with these privkeys !
wtf ?
Try with the fresh snapshot I've published above, if not just delete all except slimcoin.conf and wallet.dat in your .slimcoin folder and re-sync the whole blockchain again. To avoid deleting something that shouldn't be deleted you can just rename your .slimcoin folder and restart slimcoin-qt.