Hi!
Is there any wallet software which guarantees that private keys are always committed to disk (using appropriate kernel primitives - there must be no chance that the key is still waiting in a write-behind cache) before being used on the network?
Thanks!
This answer is sort of cheating, but any deterministic wallet (Armory, Electrum, MultiBit HD) should qualify (even if it's not because they do so explicitly), assuming you do a reboot or a sync after initial wallet creation.