You should check that you have used the correct wallet software, if the correct pass then you can dump the private key easily.
Carefully check the information!
With correct wallet software, you mean the one I used when I first installed this QT-wallet?
and it's not an issue of password.. the wallet can be unlocked without a problem, it also receives coins on the address.. and when creating a new address within the same wallet, the new address is able to retreive the private key.. it's just the original wallet address that does not seem to have that private key still attached to it.
I assume this private key is stored within the wallet.dat file?
that's why I'm looking for a way to decrypt it