I was making the assumption that the transactions aren't being accepted by the network because they are invalid, and thus have no value.  I forgot though that if the transaction includes multiple inputs but includes even one that is invalid, the client will reject the entire transaction.  

So it is possible that you still have some of the coins yet, just that the client isn't giving access to them due to them being locked up in these transactions with invalid inputs.

Thus simply exporting the private keys and importing them into a new wallet.dat would solve that.

The lazy person's solution is to use Mt. Gox's "upload wallet.dat" method and let that redeem your funds for you into your account.