Is it ok to shutdown the wallet, update it, start it again if I have coins in the Immature state?

better make a copy of the wallet.dat file before doing anything

Nah no need, just replace the Blackcoin-QT

Hey is there a wallet-client that works on windows7 64-bit? Can't seem to run any of the wallet downloads.

Yep 64-Bit isnt working.

Right click > Properties > Compatibility > Windows XP > Rejoice

Still no worky..