Thank you very much GingerAle for trying to help me
I think that this may be a bug in communication between simplewallet.exe, bitmonerod.exe and global network
May be the daemon do not receive transfer request correctly and deduct the amount from my balance but not made record for transaction in the blocchain
Therefore there are no records for transaction with id 951bbf1b602b69a038b731edd2b460cd598006d586e1256d13789ab709b95eda
I receive confirmation from wallet "2015-Feb-25 16:55:43.811316 Transaction successfully sent. <<951bbf1b602b69a038b731edd2b460cd598006d586e1256d13789ab709b95eda>>
Commission: 0.090000000000 (dust: 0.000000000000)
Balance: 38.560000000000"
But may be the daemon do not receive it
May be I have to contact Monero Dev Team
1) Backup your wallet files (.keys file should be enough, but you could backup the other files too)
2) Update your daemon/wallet to the latest version from the OP.
3) Go to "%AppData%\bitmonero" folder and rename/delete poolstate.bin
4) Go to your wallet folder and delete the wallet.bin file (NOT wallet.bin.keys)
5) Start your wallet as usual and it will be rebuild from the .keys file. Wait it to sync and your XMR should be back to your account.
6) If this doesn't work: wait 24 hours for the transaction to be removed from the mempool and then go back to 1), 2) or 3)