New Bitcoin-Qt install but can't set passphrase I have installed bitcoin-qt version 4.6.2 through the ppa:bitcoin/bitcoin ubuntu repository.  I can't set a pass-phrase because it requires a value as the old pass-phrase.  I have never created an old pass-phrase though.
Don't use that version. The client has hard forked since then, meaning that client is no longer viable for user on the network. On Linux I recommend you download source and compile the current version 0.8.6 at this time.