Lost my wallet password. Is there anything I can do?
Are you saying you still have a backup of the wallet.dat file ? If so, did you secured your bitcoin-qt 0.50 with a passphrase ? If not, install the latest version of bitcoin-qt, start the program once, exit it after it has appeared on your screen, and replace the wallet.dat file that has been created with the backup. Then restart bitcoin-qt and wait till the blockchain has been completely downloaded. This could take hours, but your BTC should appear again.