hey guys i have same problem, just opened my wallet, and don't rememeber the password, i have a copy on one USB key, but to import the file still ask me the password, and i don't remember it.
I tried all the possible password and no one is working ..
What can i do ?

Edit: I tried to create a new wallet and import from the key but i get this error "Could not depcript imput string" ...
And i have quite a lot of BTC on it

Now when i try to remove the password and i am trying possible password it give me an error "Could not decript bytes"