I have the same issue. I remember most of the password. It's just one or two characters that are off. Anyone else found a solution?
download your self a copy of backtrack 5. There are some good brute force password manipulators in there. It will give you a list of all possibilities. You just have to try them out.
I believe BT5 doesn't include this specific bruteforcer.
That said, use the pywallet script and run it with a batch file including a list of the passwords you wanted to test. That'll speed up the process.