This is one interesting case. An exported private key that cannot be imported and a wallet that doesn't sign, that does sound like a corrupted wallet. Going to follow this.
The private key has been imported into my wallet, but after this i cannot send my coins anymore.
Also i cannot dumpprivkey and import into other wallet because that gives an error.
So basicly my coins are in my current wallet but somehow i cant send them, and i cannot import the private key into an other wallet anymore.